다중 안테나 공간변조 시스템에서 낮은 복잡도를 가지는 검출 알고리즘에 관한 연구

Abstract

To improve the spectral efficiency, multi-input multi-output (MIMO) systems are widely studied with high order modulation schemes. For practical MIMO system application, it requires exponentially increased computational complexity depending on the adapted number of antenna, and inter-antenna synchronization (IAS) is essential due to simultaneous transmissions. In addition, the performance of MIMO systems could be degraded by high inter-channel interference (ICI) caused by coupling multiple symbols in time and space dimension at the receiver. In order to avoid ICI and to reduce the complexity, the spatial modulation (SM) is recently proposed. Maximum Likelihood (ML) detection algorithm is known to achieve an optimal performance for conventional communication systems and for SM as well. However, the high computational complexity still remains as a problem to be solved in case of using the large number of antennas or high modulation order. In this thesis, we propose a low-complexity detection algorithm for SM systems. The proposed detection algorithm reduces the number of possible candidates for ML detection to avoid exhaustive works. We compare the proposed algorithm and conventional algorithms both in terms of bit error rate (BER) and computational complexity. The proposed detection algorithm shows the better BER performance than the conventional algorithms even though the number of candidates is decreased.