1 *5.5.2. Effect of different fading channels*

2 Figure 13 shows the BER performance of the DS-CDMA downlink wireless communication 3 system employing the GR with the unified complex Hadamard transform spreading 4 sequences and WH spreading sequences over different channels, including the AWGN 5 channel, Rayleigh fading channel, and Ricean fading channel with the factor *F* 5 . It can be 6 seen that in all the channels under consideration, the DS-CDMA downlink wireless 7 communication system employing the GR with the unified complex Hadamard transform 8 spreading sequences has the better BER performance, especially in the high SNR region. 9 Also, we can see a great superiority under employment of the GR in the DS-CDMA 10 downlink wireless communication system with the unified complex Hadamard transform 11 spreading sequences and WH spreading sequences over the implementation of the Rake 12 receiver in the DS-CDMA downlink wireless communication system under the same 13 conditions.
