| 摘要 |
PROBLEM TO BE SOLVED: To appropriately eliminate frequency offset components even in a data pattern in which "0" and "1" do not appear equally in data. SOLUTION: An offset eliminating part 40 is provided, which branches a detection signal into first to third detection signals and uses the first to the third detection signals to perform offset elimination. The offset eliminating part is provided with a data change point detecting part 50, a one-symbol averaging circuit 42, an M-hold averaging circuit 44 and an offset subtraction circuit 46. The data change point detecting part outputs an enable signal in response to the detection of a data change point of the first detection signal. The one-symbol averaging circuit outputs an average value of each one-symbol section of an amplitude value of the second detection signal as a one-symbol average signal. The M-hold averaging circuit obtains a one-symbol average signal in response to an input of the enable signal and outputs an average value of one-symbol average signals for M times (M is positive integer) as an offset signal. The offset subtraction circuit outputs a result obtained by subtracting the offset signal from the third detection signal as an output signal. COPYRIGHT: (C)2007,JPO&INPIT
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