出版社:The Institute of Image Information and Television Engineers
摘要:The OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme is robust under multipath fading conditions. An experimental OFDM modem using the Differential Quadrature Phase Shift Keying (DQPSK) modulation scheme for each carrier has been developed to enable stable transmission of high-rate digital sources from moving vehicles. As one of the promising applications of the DQPSK-OFDM modulation scheme, a digital Field Pick-up Unit (FPU) is expected to be efficient in the case of mobile transmission. This paper describes the transmission characteristics of the DQPSK-OFDM modem in an urban area which transmits digital sources from vehicles in the UHF 800-MHz band, and also discusses the error protection scheme, the guard interval length, and the carrier spacing of the DQPSK-OFDM modem for mobile transmission.