LTE-Advanced上行SC-FDMA MIMO系统的信干噪比性能分析

LTE上行系统中,使用单载波频分多址技术(SC-FDMA),并采用离散傅里叶变换扩频的正交频分复用多址(DFT-S-OFDMA)技术作为SC-FDMA的实现方案.在LTE-Advanced标准化过程中,考虑采用DFT-S-OFDMA技术作为上行多址方案,同时,为了获得更高的峰值速率和系统性能,决定采用单用户多输入多输出(SU-MIMO)及预编码技术.针对LTE-Advanced系统上行DFT-S-OFDMA方案在MIMO系统中的应用,提出一种信干噪比(SINR)的性能分析方法.该方法基于DFT-S-OFDMA收发机实现结构,利用信道频域响应和噪声方差,接收端采用最小均方误差(MMSE)均衡,分析得到SINR的闭合表达式,获得的SINR能很好地应用于自适应调制编码(AMC)方式的选择.仿真结果表明,多径信道下基于该等效SINR的误块率(BLER)性能曲线能很好地匹配系统在高斯白噪声信道下的性能曲线.

SINR Performance Analysis of Single Carrier FDMA MIMO System in Uplink of LTE-Advanced

In the uplink of long term evolution(LTE),discrete Fourier transform spread orthogonal frequency division multiplex(DFT-S-OFDM) is used as implementation of single carrier frequency division multiple access(SC-FDMA).In the LTE-Advanced standard,DFT-S-OFDMA will still be used in the uplink to obtain high peak rate and good performance.Single user multi-input multi-output(SU-MIMO) and pre-coding are also used in SC-FDMA uplink.This paper proposes a method to analyze signal-to-interference-plus-noise ratio(SINR) performance of DFT-S-OFDMA system.A closed-form SINR expression based on transmitter-receiver implementation structure and minimum mean square error(MMSE) equalization for receiver is derived by channel frequency response and noise variance.The SINR thus obtained can be applied in adaptive modulation and coding(AMC).Simulation results show that,with the proposed equivalent SINR,the block error rate(BLER) performance of SC-FDMA over slow fading channel is well matched with that over additive white Gaussian noise(AWGN) channel.