Abstract: A pseudo noise generator includes a first arbitrary random number generator that generates two groups of first random number signals respectively corresponding to pre-divided Amplitude Probability Distributions, which are obtained by pre-dividing a specified Amplitude Probability Distribution into two parts at a specified level. A second arbitrary random number generator generates two groups of second random number signals respectively defined by a specified Pulse Duration Distribution and a specified Pulse Spacing Distribution at said specified level. One of the two groups of first random number signals are selected in accordance with the specified Pulse Duration Distribution and the specified Pulse Spacing Distribution defined at said specified level. The selected signals are converted, by a D/A converter, to pseudo noise of analog value in accordance with the Amplitude Probability Distribution, the specified Pulse Duration Distribution and the specified Pulse Spacing Distribution at the specified level.

Abstract: A pseudo noise generator is disclosed, in which a first arbitrary random number generator generates two groups of first random number signals respectively corresponding to divided Amplitude Probability Distribitions, which are obtained by dividing a specified Amplitude Probability Distribition into two parts at a specified level. A second arbitrary random number generator generates two groups of second random number signals respectively defined by a specified Pulse Duration Distribution and a specified Pulse Spacing Destribution at said specified level. Ones of said two groups of first random number signals are selected in accordance with said specified Pulse Duration Distribution and said specified Pulse Spacing-Destribution defined at said specified level.

Abstract: A start bit detecting circuit is disclosed, which employs a waveform reshaper, a detection and start circuit and a decision circuit. The waveform reshaper has threshold values T+ and T-. The detection and start circuit starts the start bit detecting circuit upon detection of a predetermined pulse width. The decision circuit judges, for a plurality of decision points, coincidence between the input signal and a specific pattern having a start-signal element, which comprises a plurality of bits.