A New Approach to Sign-Bit-Based Parameter Estimation in OFDM Receivers

摘要

This article combines algorithm development, thorough analysis and implementation of sign-bit (SB) estimation techniques for symbol timing, carrier frequency offset (CFO) and signal-to-noise ratio (SNR) in orthogonal frequency division multiplexing receivers. The SB estimation is compared in terms of performance and hardware complexity to an equivalent implementation with higher quantization. The techniques are demonstrated by simulation of a SB time/frequency and SB-SNR estimator for 3rd Generation Partnership Project long-term evolution (LTE) cell search in 65-nm technology operating at nominal voltage of 1.2 V. According to post-layout power simulations with toggling information, the architecture estimates the corresponding CFO and SNR for as little as (479,upmu hbox {W}) average power for LTE-R8/10, while occupying a silicon area as small as (0.03,hbox {mm}^2). Even though SB estimation experiences some relative performance penalty when compared to 8-bit quantization, this paper demonstrates various advantages and the potential of employing these techniques in low-complexity terminals.