Joint Detection and Decoding of Polar-Coded OFDM-IDMA Systems

Being one non-orthogonal multiple access (NOMA) scheme, interleave-division multiple access (IDMA) can increase the capacity of wireless communication, and therefore, has drawn a lot of attention. Combined with orthogonal frequency division multiplexing (OFDM), OFDM-IDMA system demonstrates good performance with low complexity. In this paper, polar codes are applied to OFDM-IDMA for further performance improvement due to its capacity-achieving capability. The corresponding joint detection and decoding (JDD) scheme is proposed as well. A sign-aided JDD (SA-JDD) scheme is introduced for better efficiency. According to numerical results, the proposed JDD scheme has 1.2 dB performance gain over the separated detection and decoding (SDD) scheme when FER is 10(-2). Compared to JDD, SA-JDD scheme reduces the computational complexity by 50% without performance degradation when SNR is 6 dB. In addition, approximation strategy and folding technique are applied for hardware-friendly implementation. The ASIC implementation has demonstrated the advantages of SA-JDD.