Research On Multi-antenna Single Carrier Frequency Domain Equalization Over Quasi-static Channels

Single-carrier frequency domain equalization(SC-FDE) is a very attractive technology to deal with the inter-symbol interference(ISI). Compared with single carrier-time domain equalization(SC-TDE) and orthogonal frequency division multiplexing(OFDM), the complexity and peak-to-average power ratio of SC-FDE are lower. However, the traditional SC-FDEs have either poor bit-error rate, or high complexity. There is trouble on tradeoff between the complexity and bit-error rate.To solve this problem, iterative block-decision feedback equalization(IB-DFE) is investigated in this thesis. IB-DFE has lower bit-error rate when the complexity is same as the traditional SC-FDEs. Based on IB-DFE, an improved scheme is proposed in this thesis. And, with the space diversity technology, the structure and performance of the IB-DFE under multi-antenna scenarios are investigated. The research includes:Firstly, two IB-DFEs: HD-IBDFE and SD-IBDFE, are analyzed theoretically and simulated respectively. The results of simulation show that HD-IBDFE and SD-IBDFE achieve about 3.0dB and 3.5dB performance improvement over traditional MMSE when bit error rate is 310- respectively.Secondly, an improved scheme of IB-DFE is studied. SD-IBDFE and energy spreading transform(EST) are combined into EST+SD-IBDFE. The results show that EST+SD-IBDFE achieves about 0.5dB performance improvement over SD-IBDFE when bit error rate is 310-.Thirdly, the implementation structures and performance of multi-antenna SD-IBDFE and EST+SD-IBDFE technology are investigated respectively. The results of simulation show that 1x2 SD-IBDFE and EST+SD-IBDFE achieve 5.0dB and 4.6dB performance improvement over 1x1 SD-IBDFE and EST+SD-IBDFE respectively. 2x1 SD-IBDFE and EST+SD-IBDFE achieve 1.4dB and 1.0dB performance improvement over 1x1 SD-IBDFE and EST+SD-IBDFE respectively. 2x2 SD-IBDFE and EST+SD-IBDFE achieve 5.5dB and 5.0dB performance improvement over 1x1 SD-IBDFE and EST+SD-IBDFE respectively.The studies of this thesis demonstrate that EST+SD-IBDFE achieves better bit-error rate than others under single antenna scenario. And the advantage decreases gradually with the increase of antenna. The results can be a reference for the research of low complexity, high performance SC-FDE technology.