Performance analysis of mimo ofdm system using various techniques under rayleigh fading channels

Abstract

The high data transmission rates in the communication channel are a growing demand in recent times, in 4G and 5G broadband wireless communication. Transmitting the signal using Single Input Single Output (SISO) method weakens the transmitting data and it is also time consuming. When the number of antennas increases using Multiple Input and Multiple Output (MIMO), the complexity and Bit Error Rate (BER) are high while concentrating to reduce the BER, the PAPR is more. For achieving the reliable communication, the Orthogonal Frequency Division Multiplexing (OFDM) technique is used with the MIMO technique. To meet the requirements of high data rate and eliminate channel impairments, MIMOOFDM is the best technique. The OFDM systems that endorse the Cyclic-Delay Diversity (CDD) scheme require an operation of Inverse Discrete Fourier transform (IDFT) at the transmitter. Hence, the CDD affords a low-complexity by means of accumulating the transmission diversity in MIMO-OFDM systems. To improve the performance of the OFDM systems, CDD is a good approach in frequency diversity. In CDD Scheme before adding the cyclic prefix the OFDM symbols and sub carriers are transmitted uniquely with different cyclic delay. So the corresponding cyclic prefix is varied for each antenna. Time delay is added during each phase shift in frequency on a frequency band. So the sub carriers are spatially different from each other with each one being slightly delayed before being received by another antenna. Thus the frequency selectivity increases and the destructive fading occurs in every subcarrier but not in the full transport block. This allows making the coding channel easy to send data. This scheme is implemented in frequency domain with a limited number of sample newline