BER Analysis of DS-CDMA Using LMS Algorithm and Rake Receiver

Sadhana Gawade; Prof. S. N. Ohatkar

CDMA is interference limited system hence the capacity of the system is limited by interference as number of users’ increases. This problem occurs when many mobile users share the same channel. CDMA takes the advantage of multipath fading .This system is resistant to multipath fading {&} also use the delayed multipath components to improve the performance of the system. This can be done using RAKE receiver in which multipath propagation delays of the transmitted signals are considered and combines the information obtained from several resolvable multipath components to form a stronger version of the signal using Rake receiver.. To overcome the problem of fading in channel Rake receiver can be used against mismatch {&} modeling errors which enhance its interference cancellation capability. This receiver consists of three stages. In the first stage, with LMS algorithm, which reduces BER i.e. there is reduction in interference. The matched filter (MF) can use for more reduction of the IPI and MAI in each RAKE finger in the second stage. In the third stage, the output signals from the matched filters can be combined according to the conventional maximal ratio combining (MRC) principle and then are fed into the decision circuit of the desired user. By measuring BER we can conclude that using rake receiver {&}LMS algorithm BER of the system for AWGN {&} Rayleigh Fading channelcan beminimized at lower SNR.

Select Volume / Issues:

• Volume 3 Issue 6, Nov. 2012

Year:

2012

Type of Publication:

Article

Keywords:

DS CDMA; Rake receiver; LMS algorithm

Journal:

IJECCE

Volume:

3

Number:

6

Pages:

1405-1409

Month:

November