caa a22 4500 606245014 CHVBK 20210128101333.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s12567-015-0094-0 doi (NATIONALLICENCE)springer-10.1007/s12567-015-0094-0 Remote-sensing satellite ground station evaluation using QPSK emulator with test pattern and PRBS generation [Elektronische Daten] [R. Srinivas, L. Nithyanandan, G. Umadevi, C. Padmavathi, Radha Nayani] In order to validate the performance of X-band (8000-8400MHz) remote-sensing satellite receive chain, when the satellite is not in the vicinity of ground station, local loop end-end evaluation tests are mandatory to certify the RF downlink and base band receive chain performance. A customised test patterns compatible to IRS satellite series and PRBS sequence are generated, which are modulated using QPSK emulator to check and verify the satellite downlink chain performance. The design and implementation are done using novel digital techniques, and QPSK modulator is integrated with Test pattern and PRBS generator using state-of-art FPGAs. The QPSK emulator output is connected to high-speed fibre optic link which transfers the signal to near field bore-site antenna system. The test signal is thus up converted from 2557.5MHz (S-band) frequency to required satellite carrier frequency of 8212.5MHz; the emulated test signal is radiated from bore-site antenna, which simulates real-time satellite data transmission from space. Thus, the signal received by the parabolic dish antenna is down converted to 720MHz, demodulated, bit synchronized, clock recovered, and frame synchronized. The evaluation of frame sync errors is done for good video data quality check. Also in the QPSK emulator, there is option of PRBS mode. Hence, using this option, the RF downlink and receive chain are evaluated for good Bit error rate (BER). The BER requirement is 1 error (tolerable) in 106 Million bits. The QPSK emulator has the provision to support different frequencies and data rates corresponding to all IRS satellite missions. CEAS, 2015 PRBS nationallicence IRS nationallicence Frame synchronizer nationallicence QPSK nationallicence BER nationallicence LNA nationallicence TPG nationallicence PRBS : Pseudo-random binary sequence nationallicence QPSK : Quadrature phase shift keying nationallicence TPG : Test pattern generation nationallicence RF : Radio frequency nationallicence IRS : Indian remote-sensing satellite nationallicence BER : Bit error rate nationallicence FS : Frame synchronizer nationallicence LCD : Liquid crystal diode nationallicence FF : Flip-flop nationallicence MUX : Multiplexer nationallicence PCB : Printed circuit board nationallicence PN : Pseudo noise nationallicence FPGA : Field programmable gate array nationallicence NRZ-L : Non-return to zero level nationallicence CCITT : Consultative committee for international telephony and telegraphy nationallicence CCSDS : Consultative committee for space data systems nationallicence XOR : Exclusive-OR gate nationallicence SLI : Serial input nationallicence CE : Clock enable nationallicence L : Load nationallicence CLR : Clear state nationallicence FC/APC : Fibre connector/angle polished connector nationallicence FO : Fibre optic nationallicence IF : Intermediate frequency nationallicence LIU : Light interface unit nationallicence IRS : Indian remote sensing nationallicence TCP/IP : Transmission control protocol/internet protocol nationallicence RRC : Root raised cosine nationallicence TD : Transition detector nationallicence AFEH : Advanced front-end hardware nationallicence CLK : Clock nationallicence LNA : Low-noise amplifier nationallicence TS : Tracking system nationallicence NCO : Numerically controlled oscillator nationallicence Srinivas R. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut Nithyanandan L. Department of Electronics and Communication Engineering, Pondicherry Engineering College, Puducherry, India aut Umadevi G. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut Padmavathi C. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut Nayani Radha Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut CEAS Space Journal Springer Vienna 7/4(2015-12-01), 399-417 1868-2502 7:4<399 2015 7 12567 https://doi.org/10.1007/s12567-015-0094-0 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s12567-015-0094-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Srinivas R. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut NATIONALLICENCE 700 1- Nithyanandan L. Department of Electronics and Communication Engineering, Pondicherry Engineering College, Puducherry, India aut NATIONALLICENCE 700 1- Umadevi G. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut NATIONALLICENCE 700 1- Padmavathi C. Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut NATIONALLICENCE 700 1- Nayani Radha Indian Space Research Organization, National Remote Sensing Centre, Hyderabad, India aut NATIONALLICENCE 773 0- CEAS Space Journal Springer Vienna 7/4(2015-12-01), 399-417 1868-2502 7:4<399 2015 7 12567