Low complexity MIMO interleaved SC-FDMA receiver using MRC with iterative detection

Abstract

In this paper we propose a low complexity receiver structure of MIMO Interleaved SC-FDMA (Multiple Input Multiple Output Interleaved Single Carrier-Frequency Division Multiple Access) on frequency selective channels. The receiver firstly obtains the tentative decision results through FDE (Frequency Domain Equalization) and using the tentative results the ISI (Inter-Symbol Interference) is cancelled by the ISI canceller. Then the MLD (Maximum Likelihood Detection) is utilized to separate the spatially multiplexed signal streams to obtain the decision results. By regarding the decision results as the improved tentative decision results, the ISI cancellation and MLD are iteratively done. However, as the complexity of MLD is quite high, we replace the MLD by the SD (Sphere Decoding). As the complexity of SD is still high for high level modulations, we adopt the combination of IAI (Inter-Antenna Interference) canceller and the MRC (Maximum Ratio Combining) instead of the SD. We examined the BER characteristics and the complexity reduction of proposed receiver structure using the ISI + IAI canceller and MRC with iterative detection and verified the effectiveness of the proposed receiver structure.