A Comparison Study for the BER in Broadband Fixed Wireless Access Systems Based on Using M-QAM

摘要

An analytical model for the bit error rate with different values of M-ary quadrature amplitude modulation (M-QAM) for broadband fixed wireless access (BFWA) is presented. The expressions/relations are derived and investigated for different values of M: 4, 8, 16, 32, 64, 128, and 256 to evaluate conditional probability of error, bit error probability and average of the probability of error. The analyses are presented for coherent and non-coherent detection schemes and comparisons between their performances are given. The achieved results show that with keeping a fixed amount of symbols energy for all considered levels/symbols the degradation in BER is remarkable with low SNR with using non-coherent detection compared with utilizing coherent one for all M-ary values. Also, less power is needed in order to achieve the same BER with utilizing non-coherent detection method.