Optimal and Simplified Viterbi Receiver for MA-SOQPSK Modulation

Multiple amplitude shaped offset quadrature phase-shift keying (MA-SOQPSK) modulation based on multiple nonlinear power amplifiers (NLPAs) provides both high power-added efficiency and spectrum efficiency. Compared with conventional 16QAM modulation, MA-SOQPSK (2 channels) modulation has much lower power consumption in the transmitter. However, the Viterbi detector contained in its receiver has high implementation complexity. An optimal receiver based on Viterbi detector is proposed to solve this problem. It cuts the correlator number from 128 to 8 in the receiver without any performance degradation. Further more, a simplified receiver structure is derived to reduce the hardware complexity significantly with very little performance degradation. The performance analysis and simulation results show that under the same BER performance, the power consumption of the MA-SOQPSK transmitter is 7.5 dB and 6.3 dB lower than the 16 QAM transmitter with the optimal receiver and the simplified receiver respectively