An SQNR Improvement Technique Based on Magnitude Segmentation for Polar Quantizers

Abstract

This paper improves the performance of the polar quantizer for wireless signals with complex Gaussian probability density functions (PDFs) first proposed by Nazari et al. A new signal-to-quantization noise ratio (SQNR) enhancement technique based on magnitude segmentation of polar space is employed, which can boost the SQNR of the quantizer significantly compared to that of the conventional rectangular and polar quantizers. First, an N-segmentation technique is examined using N different bit allocations for magnitude and phase quantizers. The study then covers a polar quantizer incorporating a three-segmentation technique for practical implementation. Using this technique, the overall maximum SQNR of the polar quantizer improves about 2.5 dB higher than the rectangular quantizer. In addition, over 14 dB SQNR improvement at low average magnitude is achieved if equal numbers of quantization levels for both polar and rectangular quantizers are utilized.