Use of LDPC to improve the MIMO-OFDM systems performance

Orthogonal frequency division multiplexing (OFDM) is a promising technique in the next evolution of the mobile telephony, However it suffers from peak to average power ratio (PAPR). It is a problem for broadcast engineers in many different applications. Non-linearities can cause severe out-of-band radiation when confronted with high PAPRs. Previous work has shown that the application of coding just before the transmission frontend can help alleviate this effect. This paper presents a design for a low density parity check (LDPC) code that achieves a good error correction performance and is used to lower the PAPR in a multiple input multiple output orthogonal frequency division multiplex system. The paper will detail the results of software simulations, verified through hardware simulations that show that further reductions in PAPR can be achieved over previous work in this field. Finally, this paper will show that PAPR reduction can be achieved by employing LDPC coding prior to modulation.