TY - GEN
T1 - Spatially superposed 64-QAM communication system
AU - Tanaka, Masayoshi
AU - Eguchi, Takuyn
PY - 2006
Y1 - 2006
N2 - We present a spatially superposed 64-quadrature amplitude modulation (QAM) communication satellite payload system that can provide efficient use of frequency resources and transmitted power. The system incorporates three conventional quadriphase shift key (QPSK) modulators and combines their output signals spatially with a specially tailored antenna array to produce a 64-QAM signal. Thus, it can operate on power amplifiers driven in the high efficiency region and relax the strict requirements for the on-board hardware as compared to conventional 64-QAM systems. The proposed system, however, is sensitive to superposition error. An antenna array system is presented that can minimize the superposition error. Results comparing conventional systems, based on theoretical studies of the signal transmission characteristics of the system, with the proposed broadband system indicated that the proposed system significantly improved power efficiency. This unique system enabled broadband transmission with efficient use of power and bandwidth.
AB - We present a spatially superposed 64-quadrature amplitude modulation (QAM) communication satellite payload system that can provide efficient use of frequency resources and transmitted power. The system incorporates three conventional quadriphase shift key (QPSK) modulators and combines their output signals spatially with a specially tailored antenna array to produce a 64-QAM signal. Thus, it can operate on power amplifiers driven in the high efficiency region and relax the strict requirements for the on-board hardware as compared to conventional 64-QAM systems. The proposed system, however, is sensitive to superposition error. An antenna array system is presented that can minimize the superposition error. Results comparing conventional systems, based on theoretical studies of the signal transmission characteristics of the system, with the proposed broadband system indicated that the proposed system significantly improved power efficiency. This unique system enabled broadband transmission with efficient use of power and bandwidth.
UR - http://www.scopus.com/inward/record.url?scp=33845195392&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:33845195392
SN - 1563478161
SN - 9781563478161
T3 - Collection of Technical Papers - 24th AIAA International Communications Satellite Systems Conference, ICSSC
SP - 318
EP - 328
BT - Collection of Technical Papers - 24th AIAA International Communications Satellite Systems Conference, ICSSC
T2 - 24th AIAA International Communications Satellite Systems Conference, ICSSC
Y2 - 11 June 2006 through 14 June 2006
ER -