High bit rate /spl pi//4-QPSK modem with a new equalizer based on sequence estimation for mobile communications

This paper proposes a new type of greatly reduced-complexity sequence estimation in which stronger power delay waves are selected and combined. The proposed method has a similar BER performance and a greatly reduced complexity than MLSE. A high-bit-rate transmission system with a rate of 10 Mbit/s, /spl pi//4-QPSK/TDM for multimedia data transmission in land mobile communications is implemented. In adopting a 4-channel TDM, a user bit rate of 2 Mbit/s can be achieved. The system can compensate for delayed waves of up to 1.8 /spl mu/sec and sustains a maximum Doppler frequency (f/sub d/) of 240 Hz.