A New Bit Timing Recovery Scheme for High Bit Rate Wireless Access

Toshiaki TAKAO  Yoshifumi SUZUKI  Tadashi SHIRATO  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E80-A   No.7   pp.1183-1189
Publication Date: 1997/07/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Multi-dimensional Mobile Information Network)
Category: 
Keyword: 
bit timing recovery,  multimedia communication,  wireless access,  TDMA/TDD system,  

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Summary: 
We propose a new bit timing recovery (BTR) scheme, what we call Step Sampled BTR (SSBTR), that can lower the sampling clock frequency and shorten the clock phase convergence time, for burst signals in high bit rate wireless access systems. The SSBTR scheme has the following characteristics. A sine wave resulting from the BTR code passing through a Nyquist Transmission System is always used, the sampling clock has a lower frequency than the system clock, and the clock phase of Intermediate Frequency (IF) signal input can be estimated from as few as 3 sampled data. The SSBTR scheme corrects the clock phase only once in a burst signal. Therefore, in some wireless access systems, some kind of operation must be performed after the SSBTR, in order to deal with long burst signals, instability of the system clock, and so on. In other wireless access systems that do not have these problems, clock phase can be fixed by the SSBTR scheme alone. The preformance of the SSBTR scheme with respect to additive white Gaussian noise (AWGN) was examined by computer simulation. In addition, when SSBTR is implemented in hardware, there are imperfections in the circuitry that lead to phase estimation error and thus deterioration, so we studied the effects of several such imperfections by computer simulation. The results of these simulations clarify the performance of the SSBTR scheme.