| 摘要 |
PROBLEM TO BE SOLVED: To allow a receiver to accurately reproduce information modulated in plural modulation systems at plural coding rates by optimizing the amplitude or the power of an input signal for each transmission system. SOLUTION: In the case of receiving and demodulating a signal in which a modulation wave modulated in plural modulation system by a BS antenna 2 is time-divided and multiplexed, a BER measurement circuit 8 measures or estimates a bit error rate in the each modulation system and a gain control circuit 9 optimizes the amplification rate of a variable gain amplifier circuit 3 based on the result of the measurement or the estimation for the every modulation system. Then the modulated wave is demodulated/decoded while the performance at the time of carrying out Viterbi decoding or trellis decoding by a trellis/Viterbi decoding circuit 7 is not deteriorated and an HDTV 19 reproduces the contents of a program sent from a transmitter.
|
