Patent ID: 8675800

Claim:
A synchronizing circuit comprising: a first phase-locked loop circuit configured to output, based on an input reception signal, a first phase control signal representing a phase control amount of said reception signal; a second phase-locked loop circuit configured to input the same signal as said reception signal input to said first phase-locked loop circuit so as to output a second phase control signal representing the phase control amount of said reception signal; a first output circuit configured to control the phase of said reception signal based on said first phase control signal so as to output the phase-controlled signal; a second output circuit configured to control the phase of said reception signal based on said second phase control signal so as to output the phase-controlled signal; a first detection circuit configured to detect a phase control error in said first phase-locked loop circuit based on the phase-controlled signal output from said first output circuit; a second detection circuit configured to detect a phase control error in said second phase-locked loop circuit based on the phase-controlled signal output from said second output circuit; a control circuit configured such that if the phase control error detected in said first phase-locked loop circuit by said first detection circuit is larger than the phase control error detected in said second phase-locked loop circuit by said second detection circuit, then said control circuit establishes the same value as the loop gain of a second loop filter included in said second phase-locked loop circuit as the loop gain of a first loop filter included in said first phase-locked loop circuit; and a holding section configured to hold a loop gain setting established as the loop gain of said first loop filter included in said first phase-locked loop circuit; wherein said reception signal is structured in units of a frame made up of a plurality of slots transmitted in a plurality of transmission modes corresponding to different modulation techniques, and said holding section holds said loop gain setting for each of said transmission modes.