| 摘要 |
Two signals of different frequency, after having been received, are optionally amplified or attenuated in a fading compensation amplifier (1), then separated from one another by means of bandpass filters (2, 5) and amplitude-demodulated by means of envelope curve detectors (3, 6), whereupon the envelope curve signals (z0[t], z1[t]) are sampled once per bit by means of sampling switches (4, 7) in order to obtain samples (z0[kTb], z1[kTb]) which are supplied to a computer unit (8), in the memory of which values of a decision table are stored which are derived from a probability table. Each table field of the latter contains two probability values, a first one of which is the probability that the samples (z0[kTb], z1[kTb]) are located within the relevant table field when the first signal has been sent, and a second of which is the probability that the samples (z0[kTb], z1[kTb]) are located within the relevant table field when the second signal has been sent. A first logic value is in each case entered in a table field of the decision table when the first probability value is greater than the second probability value, and a second logic value is entered when the first probability value is less than or equal to the second probability value. The method combines the advantages of the incoherent demodulation method and of the spreadband method. <IMAGE>
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