| 摘要 |
PURPOSE:To adjust a synchronous optimum receiver, where a function table is addressed in accordance with the contents of a receiving signal and synchronizing pattern data and specific functional data read out from the table is used to perform a maximum likelihood test, with a simple digital circuit prepared for adjusting. CONSTITUTION:The probability density function P(Z) of noise of an objective communication line is preliminarily analyzed and grasped, and the logP(Z) obtained by the logarithmic conversion of this function is stored as a function table 3 in a memory. When the function table 3 is addressed by the output of a subtracting circuit 7, data logP(Xn-S2n) and data logP(Xn-S1n) are read out alternately from the table 3. This data passes a code inverting circuit 8 and is inputted to a totaling circuit 9. The totaling circuit 9 accumulates input data successively and is reset by the output B of a decoder 6. A discriminating circuit 10 compares data (y), which is outputted from the totaling circuit 9 then, with 0 synchronously with the output A of the decoder 6 to output demodulated data RD. |
