Performance comparison Bit Error Rate and capacity analysis of Raleigh & Rician Fading Wireless communication System

Abstract

Cognitive radio (CR) is an advanced technology in order to identify the number of unused channels in the
wireless spectrum. This will also shares the spectrum between primary user (PU) and secondary user
(SU) in efficient way. The secondary user can coexist with primary user to form the cognitive radio
network (CRN). While allocating the spectrum between the users the fading problem may occur. Here we
examined the techniques of maximizing ergodic capacity in different fading channel like Rayleigh fading
and Rician fading techniques. In order to minimize the transmission error and by using optimum power
allocation for calculation of Ergodic system capacity and outage system capacity in Multiple Input and
Multiple Output (MIMO). This examination incorporates the Bit Error Rate (BER) execution of Space
Time Block Codes (STBC) with Alamouti code for the remote channels like Rayleigh and Rician with
QPSK modulation plan. Lagrangian multiplier algorithm and water filling algorithm is used to calculate
the power allocation schemes with numerical value and its is observed that water filling algorithm
produces better then Lagrangian multiplier algorithm. After analyzing the channel capacity the bit error
rate of the channel is calculated