14 **4.1. Brief review**

36 BookTitle

5 with the transfer function

114 Contemporary Issues in Wireless Communications

8 perfect power control.

9

11 **3.6. Conclusions**

1 Figure 8 demonstrates the optimal PCF versus the number of users both for the synchronous 2 AWGN and for the multipath channels. We carry out simulation for the AWGN channel 3 under the following conditions: the Gold codes, *SNR*=12 dB, the spreading codes are the 4 periodic and perfect power control. The multipath channel assumed is a two-ray channel

<sup>2</sup> ( ) 0.762 0.648 <sup>6</sup>*Wk Z Z* (138)

7 for all users. In the case of multipath channel, we employ aperiodic codes, *SNR* =12 dB, and

10 **Figure 8.** Optimal PCF versus the number of users: the AWGN and multipath channels.

12 The GR performance with quadrature subbranch HS/MRC and HS/MRC schemes for a 1-D 13 signal modulation in Rayleigh fading was investigated. The SER of *M*-ary PAM, including 14 coherent BPSK modulation, was derived. Results show the GR with quadrature subbranch 15 HS/MRC and HS/MRC schemes performs substantially better the GR with traditional 16 HS/MRC scheme, particularly, when *L* is smaller than one half *N*, and much better the 17 traditional HS/MRC receiver. We have also derived the optimal PCF range for GR first stage 18 based on the PPIC, which is employed by DS-CDMA system, with hard decisions in 19 multipath fading channel. Computer simulation shows that the BER performance of the GR 20 employed by DS-CDMA wireless communication system with multipath fading channel in 21 the case of periodic code scenario and using the average of the lower and upper boundary 22 values is close to that of the GR of the case using the real optimal PCF, whether the SNR is 23 high or low. It has also been shown that GR employment in DS-CDMA system with 24 multipath fading channel in the case of periodic code scenario allows us to observe a great 15 In this section, we consider and study the GR in DS-CDMA wireless communication system 16 with frequency-selective channels. We discuss the linear equalization with the finite impulse 17 response (FIR) beamforming filters and channel estimation and spatially correlation.
