{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2025-12-14T01:33:56.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2025-12-14T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":45806,"title":"SatCom #8: Satellite Link Budget ","description":"Satellite and Space Engineering - Problem #8\r\nThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\r\nlf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\r\nKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\r\nYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \r\nHint: See https://en.wikipedia.org/wiki/Link_budget#Equation - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\r\nExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\r\nSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 399px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 199.5px; transform-origin: 407px 199.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 150.092px 7.75px; transform-origin: 150.092px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003eSatellite and Space Engineering - Problem #8\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 360.592px 7.75px; transform-origin: 360.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 382.633px 7.75px; transform-origin: 382.633px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 381.592px 7.75px; transform-origin: 381.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.425px 7.75px; transform-origin: 380.425px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 28.7833px 7.75px; transform-origin: 28.7833px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eHint: See\u003c/span\u003e\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 1.94167px 7.75px; transform-origin: 1.94167px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"https://en.wikipedia.org/wiki/Link_budget#Equation\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003ehttps://en.wikipedia.org/wiki/Link_budget#Equation\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 186.308px 7.75px; transform-origin: 186.308px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 7.75px; transform-origin: 384px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.433px 7.75px; transform-origin: 380.433px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function p = link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq)\r\n  p = txpower+txdiam+rxdiam+txeff+rxeff+pathlength+freq;\r\nend","test_suite":"%% GSO Case from example\r\ntxpower=9.5;\r\ntxdiam=0.75;\r\nrxdiam=0.65;\r\ntxeff=70;\r\nrxeff=65;\r\npathlength=41130.13;\r\nfreq=17.7;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -119.1187;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% S-Band NGSO\r\ntxpower=0.5;\r\ntxdiam=0.15;\r\nrxdiam=0.45;\r\ntxeff=70;\r\nrxeff=60;\r\npathlength=500;\r\nfreq=1.5;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -128.7736;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% W-Band MGSO\r\ntxpower=10;\r\ntxdiam=0.2;\r\nrxdiam=0.75;\r\ntxeff=75;\r\nrxeff=60;\r\npathlength=10525;\r\nfreq=76;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -104.4088;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% Earth-Moon Link at L-band\r\ntxpower=12;\r\ntxdiam=1.2;\r\nrxdiam=12.4;\r\ntxeff=75;\r\nrxeff=65;\r\npathlength=384400;\r\nfreq=1.6;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -126.9161;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% Block obvious cheats\r\ns=importdata('link_budget.m');\r\ny_correct=false;\r\nassert(isequal(sum(contains(s,'regexp')),y_correct),'Regexp not allowed');\r\nassert(isequal(sum(contains(s,'assert')),y_correct), 'Assert not allowed');","published":true,"deleted":false,"likes_count":3,"comments_count":1,"created_by":437780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":42,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-09T20:07:25.000Z","updated_at":"2026-04-02T19:06:40.000Z","published_at":"2022-01-04T15:40:10.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSatellite and Space Engineering - Problem #8\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHint: See\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Link_budget#Equation\\\"\u003e\u003cw:r\u003e\u003cw:t\u003ehttps://en.wikipedia.org/wiki/Link_budget#Equation\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":45809,"title":"SatCom #9: Overall Link Performance ","description":"Satellite and Space Engineering - Problem #9\r\nThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\r\nlf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\r\nKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\r\nYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\r\nHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\r\nExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 dB.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 390px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 195px; transform-origin: 407px 195px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 150.092px 7.75px; transform-origin: 150.092px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003eSatellite and Space Engineering - Problem #9\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 360.592px 7.75px; transform-origin: 360.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 382.633px 7.75px; transform-origin: 382.633px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.375px 7.75px; transform-origin: 380.375px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.425px 7.75px; transform-origin: 380.425px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 383.158px 7.75px; transform-origin: 383.158px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 84px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 42px; text-align: left; transform-origin: 384px 42px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 7.75px; transform-origin: 384px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 dB.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function cton = link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp)\r\n  cton = txpower+txdiam+rxdiam+txeff+rxeff+pathlength+freq+rxbandwidth+rxtemp;\r\nend","test_suite":"%% GSO Case from example\r\ntxpower=9.5;\r\ntxdiam=0.75;\r\nrxdiam=0.65;\r\ntxeff=70;\r\nrxeff=65;\r\npathlength=41130.13;\r\nfreq=17.7;\r\nrxbandwidth=10;\r\nrxtemp=220;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 6.0562;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% S-Band NGSO\r\ntxpower=0.5;\r\ntxdiam=0.15;\r\nrxdiam=0.45;\r\ntxeff=70;\r\nrxeff=60;\r\npathlength=500;\r\nfreq=1.5;\r\nrxbandwidth=0.05;\r\nrxtemp=180;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 20.2831;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% W-Band MEO\r\ntxpower=10;\r\ntxdiam=0.2;\r\nrxdiam=0.75;\r\ntxeff=75;\r\nrxeff=60;\r\npathlength=10525;\r\nfreq=76;\r\nrxbandwidth=50;\r\nrxtemp=315;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 12.2175;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% Earth-Moon Link at L-band\r\ntxpower=12;\r\ntxdiam=1.2;\r\nrxdiam=12.4;\r\ntxeff=75;\r\nrxeff=65;\r\npathlength=384400;\r\nfreq=1.6;\r\nrxbandwidth=20;\r\nrxtemp=125;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = -2.2963;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% Block obvious cheats\r\ns=importdata('link_performance.m');\r\ny_correct=false;\r\nassert(isequal(sum(contains(s,'regexp')),y_correct),'Regexp not allowed');\r\nassert(isequal(sum(contains(s,'assert')),y_correct), 'Assert not allowed');","published":true,"deleted":false,"likes_count":1,"comments_count":3,"created_by":437780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":33,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-09T20:08:17.000Z","updated_at":"2026-04-02T19:23:51.000Z","published_at":"2022-01-04T17:03:30.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSatellite and Space Engineering - Problem #9\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 dB.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"}],"problem_search":{"errors":[],"problems":[{"id":45806,"title":"SatCom #8: Satellite Link Budget ","description":"Satellite and Space Engineering - Problem #8\r\nThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\r\nlf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\r\nKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\r\nYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \r\nHint: See https://en.wikipedia.org/wiki/Link_budget#Equation - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\r\nExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\r\nSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 399px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 199.5px; transform-origin: 407px 199.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 150.092px 7.75px; transform-origin: 150.092px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003eSatellite and Space Engineering - Problem #8\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 360.592px 7.75px; transform-origin: 360.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 382.633px 7.75px; transform-origin: 382.633px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 381.592px 7.75px; transform-origin: 381.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.425px 7.75px; transform-origin: 380.425px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 28.7833px 7.75px; transform-origin: 28.7833px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eHint: See\u003c/span\u003e\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 1.94167px 7.75px; transform-origin: 1.94167px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"https://en.wikipedia.org/wiki/Link_budget#Equation\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003ehttps://en.wikipedia.org/wiki/Link_budget#Equation\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 186.308px 7.75px; transform-origin: 186.308px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 7.75px; transform-origin: 384px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.433px 7.75px; transform-origin: 380.433px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function p = link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq)\r\n  p = txpower+txdiam+rxdiam+txeff+rxeff+pathlength+freq;\r\nend","test_suite":"%% GSO Case from example\r\ntxpower=9.5;\r\ntxdiam=0.75;\r\nrxdiam=0.65;\r\ntxeff=70;\r\nrxeff=65;\r\npathlength=41130.13;\r\nfreq=17.7;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -119.1187;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% S-Band NGSO\r\ntxpower=0.5;\r\ntxdiam=0.15;\r\nrxdiam=0.45;\r\ntxeff=70;\r\nrxeff=60;\r\npathlength=500;\r\nfreq=1.5;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -128.7736;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% W-Band MGSO\r\ntxpower=10;\r\ntxdiam=0.2;\r\nrxdiam=0.75;\r\ntxeff=75;\r\nrxeff=60;\r\npathlength=10525;\r\nfreq=76;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -104.4088;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% Earth-Moon Link at L-band\r\ntxpower=12;\r\ntxdiam=1.2;\r\nrxdiam=12.4;\r\ntxeff=75;\r\nrxeff=65;\r\npathlength=384400;\r\nfreq=1.6;\r\nrxpower=link_budget(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq);\r\ny_correct = -126.9161;\r\nassert(abs(rxpower-y_correct)\u003c0.0001)\r\n\r\n%% Block obvious cheats\r\ns=importdata('link_budget.m');\r\ny_correct=false;\r\nassert(isequal(sum(contains(s,'regexp')),y_correct),'Regexp not allowed');\r\nassert(isequal(sum(contains(s,'assert')),y_correct), 'Assert not allowed');","published":true,"deleted":false,"likes_count":3,"comments_count":1,"created_by":437780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":42,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-09T20:07:25.000Z","updated_at":"2026-04-02T19:06:40.000Z","published_at":"2022-01-04T15:40:10.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSatellite and Space Engineering - Problem #8\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eKnowing the parameters of a radio transmitter and receiver, determine the wanted signal power (dBW) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). \u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHint: See\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Link_budget#Equation\\\"\u003e\u003cw:r\u003e\u003cw:t\u003ehttps://en.wikipedia.org/wiki/Link_budget#Equation\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e - For this simplified exercise, you should ignore transmitter, receiver and miscelaneous losses.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, the RF power in the satellite receiver is around -119.1 dBW.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSome future problems in this series will build on work done in previous problems, so if you get a working solution I suggest you hang onto the code!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":45809,"title":"SatCom #9: Overall Link Performance ","description":"Satellite and Space Engineering - Problem #9\r\nThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\r\nlf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\r\nKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\r\nYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\r\nHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\r\nExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 dB.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 390px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 195px; transform-origin: 407px 195px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 150.092px 7.75px; transform-origin: 150.092px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003eSatellite and Space Engineering - Problem #9\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 360.592px 7.75px; transform-origin: 360.592px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 382.633px 7.75px; transform-origin: 382.633px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-style: italic; \"\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.375px 7.75px; transform-origin: 380.375px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 380.425px 7.75px; transform-origin: 380.425px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 21px; text-align: left; transform-origin: 384px 21px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 383.158px 7.75px; transform-origin: 383.158px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 84px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 42px; text-align: left; transform-origin: 384px 42px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 384px 7.75px; transform-origin: 384px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 dB.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function cton = link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp)\r\n  cton = txpower+txdiam+rxdiam+txeff+rxeff+pathlength+freq+rxbandwidth+rxtemp;\r\nend","test_suite":"%% GSO Case from example\r\ntxpower=9.5;\r\ntxdiam=0.75;\r\nrxdiam=0.65;\r\ntxeff=70;\r\nrxeff=65;\r\npathlength=41130.13;\r\nfreq=17.7;\r\nrxbandwidth=10;\r\nrxtemp=220;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 6.0562;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% S-Band NGSO\r\ntxpower=0.5;\r\ntxdiam=0.15;\r\nrxdiam=0.45;\r\ntxeff=70;\r\nrxeff=60;\r\npathlength=500;\r\nfreq=1.5;\r\nrxbandwidth=0.05;\r\nrxtemp=180;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 20.2831;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% W-Band MEO\r\ntxpower=10;\r\ntxdiam=0.2;\r\nrxdiam=0.75;\r\ntxeff=75;\r\nrxeff=60;\r\npathlength=10525;\r\nfreq=76;\r\nrxbandwidth=50;\r\nrxtemp=315;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = 12.2175;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% Earth-Moon Link at L-band\r\ntxpower=12;\r\ntxdiam=1.2;\r\nrxdiam=12.4;\r\ntxeff=75;\r\nrxeff=65;\r\npathlength=384400;\r\nfreq=1.6;\r\nrxbandwidth=20;\r\nrxtemp=125;\r\ncton=link_performance(txpower, txdiam, rxdiam, txeff, rxeff, pathlength, freq, rxbandwidth, rxtemp);\r\ny_correct = -2.2963;\r\nassert(abs(cton-y_correct)\u003c0.0001)\r\n\r\n%% Block obvious cheats\r\ns=importdata('link_performance.m');\r\ny_correct=false;\r\nassert(isequal(sum(contains(s,'regexp')),y_correct),'Regexp not allowed');\r\nassert(isequal(sum(contains(s,'assert')),y_correct), 'Assert not allowed');","published":true,"deleted":false,"likes_count":1,"comments_count":3,"created_by":437780,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":33,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-09T20:08:17.000Z","updated_at":"2026-04-02T19:23:51.000Z","published_at":"2022-01-04T17:03:30.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eSatellite and Space Engineering - Problem #9\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis is part of a series of problems looking at topics in satellite and space communications and systems engineering.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003elf you have competed the previous exercises in this series, you will have more-or-less everything that you need to complete this problem.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eKnowing the parameters of a radio transmitter and receiver, determine the received signal 'quality' expresed as a carrier-to-noise ratio (in dB) in the radio receiver (in this case we are thinking of a satellite receiver, but the approach is generic to all radio receivers).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given power (dBW) of the signal applied to the transmitting dish antenna, the diameters (m) and efficiencies (%) of the transmitting and receiving dishes, the path length (km) between the transmitting and receiving antennas, and the frequency of the transmitted signal (GHz). You are also given the receiver noise tempterature (K) and bandwidth (MHz).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eHint: The carrier-to-noise ratio is the ratio between the received signal power in the radio receiver (see Problem #8) and the thermal noise in the receiver (see Problem #7). Typically it will be expressed in dB terms.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample: For a Ka-Band GSO space-to-Earth link at 17.7 GHz and of path length 41,130.13 km, where the satellite antenna has an input RF power of 9.5 dBW, a diameter of 75cm and an efficiency of 70%, and the signal is received on an Earth-station antenna of diameter 65cm and efficiency 65%, and where the receiver has a bandwidth of 10 MHz and a noise temperature of 220 K, the carrier-to-noise ratio in the satellite receiver is around 6.1 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