Abstract
This Paper describes the performance Evaluationof Physical layer (PHY) in WLAN System. A MATLABsimulation is carried out on WLAN baseband processor /transceiver. Orthogonal Frequency Division Multiplexing(OFDM) is applied in this project according to the IEEE802.11 a standard, which allows Transmission of data ratesfrom 6Mbps up to 54 Mbps. Distinct modulation schemes asBinary Phase Shift Keying (BPSK), Quadrate Phase ShiftKeying (QPSK) and Quadrature Amplitude modulation(QAM) are used according to differing data Rates for Signalvisualization at each block of Transceiver. Simulation iscarried to measure Bit Error Rate (BER), Symbol error rate& to measure Number of data bits, coded bits in OFDMsymbol by using different modulation & Code rate. OurInvestigations show that there is significant room forimprovement and therefore we propose an enhancement tothe Channel coding scheme. By application of Shannon-limitapproaching Convolution codes we yield a Performance gainof about 4 dB at the reference BER of 10-5. Furthermore,our proposal leads to a convenient and expedient PHY andincreases the system efficiency.