Coded MIMO -OFDM Using LDPC Code over Fading Channels

Abstract

The combination of multiple input multiple output (MIMO) with orthogonal frequency division
multiplexing (OFDM) is one of the main wireless communication technologies for fourth-generation ( 4 G).
It has ability to overcome inter symbol interference (ISI) and frequency selective fading of channel, increase
system capacity and obtain maximum spectral efficiency. Forward error correction (FEC) can be used to
detect and correct errors that occur during data transmission, thereby improving the performance of MIMOOFDM. In this paper uses Low Density Parity Check (LDPC) to simulate the performance of the MIMOOFDM system with space time block code (STBC) exploiting the benefits of Maximal Ratio Combining
(MRC) over fading channel. Low-density parity check (LDPC) code is one of forward error correction
(FEC) codes that can improve system reliability. MIMO-STBC-OFDM and MRC together can be used with
LDPC codes for different digital modulation which are binary phase shift Keying (BPSK), Quadrature Phase
Shift Keying (QPSK), Quadrature Amplitude Modulation (16-QAM) and (64-QAM) to ensure fair
investigation. The received signals from several paths are weighted and combined, in accordance with the
MRC scheme, and the performance is further maximized by increasing the signal-to-noise ratio (SNR) of
the MIMO-OFDM system. Results of the simulation show that the suggested MIMO-OFDM system is
combined with STBC-MRC with LDPC (coded) obtain better performance than un-coded MIMO-OFDM .