OFDM for 4G Wireless Communications

Abstract

Orthogonal frequency division multiplexing(OFDM) is the multiple access scheme for the fourth generation(4G) wireless communications. This paper analyzes the performance of OFDM through the Bit Error Rate(BER), Outage Probability, and ergodic capacity with flat delay profile as well as linearly increasing power decay factor. The probability density function(PDF) obtained in a Rayleigh fading channel is used to derive a closed-form expression for the outage probability, error rates and ergodic capacity of OFDM signals. The exact error rate values are similar to those obtained from simulation results. The performance improves with more number of channel taps

MIMO-OFDM in a Cooperative Frequency Selective Fading Channel: An Analysis

“…e closed-form expressions for BER and P out for the direct link are specified in (17) and (18), respectively. e results obtained from (13) and (16)- (18) are plotted and compared with the simulation values.…”

“…We start our modeling by taking the probability density function (PDF) of a Rayleigh frequency selective channel de ned in (1) as described by Dixit and Katiyar in 2018 [17]:…”

“…. For the direct link between the source and destination, the closed-form expression for P out has been derived by Dixit and Katiyar in 2018 [17] and expressed as follows:…”

“…where M t M d is the order of diversity, c is the average fading power as described in (13), gammainc(•, •) is the incomplete gamma function, and c th is the threshold SNR. e closedform expression for BER is derived by Dixit and Katiyar [17] and expressed as…”

“…here a � 1/4ΩS, c � b/2a, m � M t M d , and b � 2. In (17) and (18), c and Ω represent the average fading power and are a function of power decay factor as described in (13).…”