Performance of MIMO-OFDM Transmission System on Wireless Networks

A detailed study of the performance of MIMOOFDM transmission on WLAN physical layer specified in IEEE 802.11n, Wi-MAX (IEEE 802.16-2009) physical layer specified in 802.16 and LTE downlink physical channel (PDSCH) has been carried out using MATLAB Simulink. The WLAN and Wi-MAX system incorporates Convolution coding with 1/2 and 2⁄3 rated codes. The LTE incorporates Turbo coding with 1/2 and 2/3 rated codes. Orthogonal Frequency Division Multiple (OFDM) accesses uses adaptive modulation technique such as QPSK,16-QAM and 64QAM, on the physical layer of WLAN, Wi-MAX and LTE and the concept of cyclic prefix that adds additional bits at the transmitter end. The Error Rate (BER) derived from simulation results show that the implementation with interleaved Convolution coding and Turbo coding under QPSK modulation technique is found to be highly efficient for WLAN, Wi-MAX and LTE wireless network system. The Implementation of MIMO–OFDM multiplexing on WLAN networks with QPSK modulation at BER ~10 dB, exhibits significant improvement in SNR ~ 2.75 dB, WiMAX network SNR ~ 3.75 dB and LTE network SNR ~7.55 dB. The improvement of SNR ~4.8 dB displayed between the MIMO-OFDM implementation on WLAN and LTE network can be attributed to the Turbo coding techniques adopted in LTE networks. Keywords-Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Phase Shift Keying (PSK), Quadrature Amplitude modulation (QAM), Bit Error Rate (BER), Signal to Noise Ratio (SNR), Line-of-Sight (LoS), Forward Error Correction (FEC), Wireless Local Area Network (WLAN), Worldwide interoperability for Microwave Access (WiMAX), Long Term Evaluation (LTE), Subscriber Station (SS), Base Station (BS).