Symbol timing detector and wireless terminal

Abstract

A wireless terminal detects the symbol timing in a received modulated signal and demodulates the signal. Symbol timing can be stably controlled, even when frequency deviation occurs in the wireless communication frequencies. Sampling means samples signal values of the modulated signals at a period that is shorter than the symbol period. An extraction means extracts, from a plurality of sampling points, what are taken to be signal values at symbol timing points, and sampling point demodulation means performs demodulation with respect to signal values at each sampling point. A value detection means is used to detect the power value at each sampling point resulting from the demodulation. Symbol timing control means are used to control the timing taken to be symbol timing by the extraction means, based on the power values at the sampling points.

Description

field of invention [0001] The present invention relates to a wireless device, in particular to a wireless device with synchronous symbol timing. In particular, the present invention relates to a method of detecting symbol timing for establishing symbol synchronization in the case of demodulation of digitally modulated signals. Background technique [0002] The receiver of the digital modulation system needs to achieve symbol timing synchronization in order to demodulate the received signal and obtain the signal information accurately. Unless the symbol timing at the transmitter and the symbol timing at the receiver are synchronized, the information demodulated by the receiver will contain errors. [0003] To synchronize symbol timing, in the case of π / 4-phase-shifted QPSK systems, for example, the method of detecting symbol timing involves differential detection of the received baseband signal and the baseband quadrature component (Q component) and inphase component (I comp...

AI Technical Summary

Problems solved by technology

In I-component zero-crossing detection, for example, frequency deviations that cause the phase point to o

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