Analytical characterization of CSI quantization effects on broadband multipath channels

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• 作者：Sara Teodoro^a ; ^{steodoro@av.it.pt" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Adã ; o Silva^a ; ^{asilva@av.it.pt" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Rui Dinis^b ; ^{rdinis@fct.unl.pt" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Atí ; lio Gameiro^a ; ^{amg@ua.pt" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Channel state information ; Nonlinear distortion ; Quantization errors ; Limited feedback
• 刊名：Digital Signal Processing
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：60
• 期：Complete
• 页码：360-369
• 全文大小：751 K

文摘

The knowledge of channel state information (CSI) at transmitter is crucial in precoding techniques to efficiently explore wireless multiuser multi-antenna capabilities namely to mitigate the interference and/or to separate spatial streams. For frequency division duplex systems, the CSI available is a quantized version fed back from the receivers, and the nonlinear effects associated to CSI quantization can lead to significant performance degradation. The knowledge of the statistical characteristics of those nonlinear distortion effects is important for performance evaluation purposes, as well as to design robust precoding techniques.

In this paper we consider a general broadband multipath channel sampled in the frequency domain and obtain the analytical statistical characterization of the nonlinear distortion effects associated to CSI quantization. Our analytical approach is valid for non-uniform quantizers, and it also includes quantizer saturation and channel oversampling effects. It provides a detailed statistical characterization in time and frequency domains, associated to the channel impulse and frequency responses, respectively. The derived theoretical statistical characterization of quantization distortion is validated by simulation, showing its high accuracy. As an application, we consider a multicarrier transmission employing a precoding technique with reduced feedback techniques employing a small number of quantization bits per channel sample.