| 摘要 |
PURPOSE:To detect a reception error rate accurately by performing detection operation again automatically when a detected reception error rate exceeds a prescribed value. CONSTITUTION:A received signal is sampled and slightly delayed by delay and sampling circuit 20, whose output is supplied to comparison signal generating circuit 23. By a clock pulse outputted from clock gate circuit 21 as a reference pulse and a gate pulse in the initial 16-bit period outputted from gate pulse generating circuit 22, circuit 23 is initialized with the 1st 16-bit received signal and then generates a PN signal for comparison. Comparing circuits 24 and 28 compare the output of circuit 20 with that of circuit 23, bit by bit; circuit 24, when both signals disagree, outputs a dissidence signal and circuit 28, when both the signals agree, outputs a coincidence signal. Counting circuit 29 counts the coincidence signal and, when the rate of coincidence in a random period does not reach a prescribed value, sends a reset pulse to actuating circuit 30 to perform detection operation again. |
