Patent ID: 7149491

Claim:
A radio reception apparatus for receiving a signal subjected to multivalued modulation, and effecting digital processing on the received signal, comprising: a signal converter connected to receive the signal subjected to multivalued modulation as an input signal and convert said input signal to a first digital signal having a first sampling frequency; a frequency converter connected to receive said first digital signal and to produce a second digital signal having a second sampling frequency; a symbol timing detector connected to receive said second digital signal and to detect a timing of a symbol point in said second digital signal; a signal extractor connected to receive said second digital signal and to extract the symbol point of said detected timing from said second digital signal; a signal processor connected to receive the output of the signal extractor and to effect predetermined digital signal processing on said extracted symbol point; and a timing deviation detector connected to receive the second digital signal and to detect a deviation of the timing of said symbol point detected by said symbol timing detector from timing of a correct symbol point, wherein said frequency converter controls the timing of sampling of said first digital signal in accordance with the deviation of the timing detected by said timing deviation detector such that said symbol timing detector detects the symbol point at the timing of the correct symbol point; wherein said symbol timing detector determines timing when a correlation value between said second digital signal and a predetermined reference signal takes a maximum value as the timing of the symbol point in said second digital signal; and wherein said timing deviation detector calculates a magnitude and a direction of said deviation based on a relationship between magnitudes of the correlation values preceding and following said maximum value, respectively, and a magnitude of said maximum value.