Discrete Polyphase Matched Filtering-Based Soft Timing Estimation for Mobile Wireless Systems
In this paper the authors present a Soft Timing Phase Estimation (STPE) method for wireless mobile receivers operating in low Signal to Noise Ratios (SNRs). Discrete Polyphase Matched (DPM) filters, a Log-Maximum A Posterior probability (MAP) and/or a Soft-Output Viterbi Algorithm (SOVA) are combined to derive a new Timing Recovery (TR) scheme. They apply this scheme to wireless cellular communication system model that comprises of a Raised Cosine Filter (RCF), a Bit-Interleaved Turbo-coded Multi-level Modulation (BITMM) scheme and the channel is assumed to be memory-less. Furthermore, no clock signals are transmitted to the receiver contrary to the classical Data Aided (DA) models. This new model ensures that both the bandwidth and power of the communication system is conserved.