Multi-Rate OFDM Transceiver Analysis in AWGN and Rayleigh Channels

Orthogonal Frequency Division Multiplexing (OFDM) plays a major role in today’s wireless communications systems, using which data can be transmitted in multi band with high data rate and without interference. UWB (ultra wideband) systems used for multimedia applications use multiband (MB) OFDM for this purpose. In this paper, we initially build up OFDM UWB Transmitter and Receiver which includes scrambling, encoding, puncturing, QPSK modulation, IFFT at Transmitter and their reverse operational blocks at the Receiver. The focus of this paper is to achieve multi rate OFDM UWB Transceiver by varying the puncturing/de puncturing rates to obtain different code rates while using the same encoder and decoder. The effect of different code rates in different channels (i.e. AWGN and Raleigh fading channels) with respect to BER (bit error rate) are tested to analyse the performance of the code rates (1/2, 8/23, 4/7, 2/3) in AWGN and Rayleigh fading channels.