Accurate FFT processing window timing detection based on maximum SIR criterion in OFCDM wireless access
Accurate FFT processing window timing detection based on maximum SIR criterion in OFCDM wireless access
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OFCDM无线接入中基于最大SIR准则的精确FFT处理窗口定时检测
DOI：
10.1093/ietcom/e88-b.2.552
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
M. Sawahashi
中科院分区：
文献类型：
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作者：
Satoshi Nagata;N. Maeda;H. Atarashi;M. Sawahashi
针对正交频分码分复用（OFCDM）无线接入中检测到的FFT窗定时不同的情况，提出了一种基于最大信干比（SIR）准则的FFT窗定时精确检测方法，该方法综合考虑了接收信号功率和码间干扰。使用期望信号功率和符号间干扰功率来估计FFT处理后的接收信号的SIR，该符号间干扰功率使用通过导频符号副本和接收信号之间的互相关测量的功率延迟分布来计算。此外，由于仅针对第一路径和超过保护间隔持续时间的那些路径的接收路径定时（其大于噪声阈值）计算SIR，所以所提出的方法的计算复杂度低。计算机仿真结果表明，该方案降低了所需的每符号平均接收信号能量与背景噪声功率谱密度比（E/sub s//N/sub 0/），与检测功率延迟分布的前向路径定时的传统方法相比，用于实现10/sup-2/的平均分组差错率（PER）大约1.0 dB（16 QAM数据调制，六径瑞利衰落信道，最大延迟时间为3微秒，RMS延迟扩展为0.86微秒）。
The paper proposes an accurate fast Fourier transform (FFT) window timing detection method based on the maximum signal-to-interference power ratio (SIR) criterion, taking into account the received signal power and intersymbol interference, according to different detected FFT window timings in orthogonal frequency and code division multiplexing (OFCDM) wireless access. The SIR of the received signal after FFT processing is estimated using the desired signal power and the intersymbol interference power calculated using the power delay profile, which is measured by the cross-correlation between the pilot symbol replica and the received signal. Furthermore, since the SIR is calculated only for the received path timing of the first path and those paths exceeding the guard interval duration, which are greater than the noise-threshold value, the computational complexity of the proposed method is low. Computer simulation results show that the proposed scheme reduces the required average received signal energy per symbol-to-background noise power spectrum density ratio (E/sub s//N/sub 0/) for achieving the average packet error rate (PER) of 10/sup -2/ by approximately 1.0 dB compared to the conventional method which detects the forward path timing of the power delay profile (16QAM data modulation, six-path Rayleigh fading channel, maximum delay time of 3 microsec, RMS delay spread of 0.86 microsec).