Abstract: Techniques are disclosed for converting a multibit digital data word into a corresponding analog signal. The converter of the present invention utilizes information in a received signal plus noise associated with the information in such a manner as to reduce the mean squared error in the generated analog signal. The actual voltage associated with each bit position in the digital word is measured. In addition, a measurement of the signal-to-noise ratio is made. From these two measurements a processing device is adapted to generate a value corresponding to the statistical probability that the detected voltage level for each bit is a logical one. The probability values are used as scaling factors to modify the weights to be given each bit during the normal digital to analog conversion process.

Abstract: In this pcm digital-to-analog converter, a probability value (soft decision), rather than the conventional one/zero value (hard decision), is given each sampled input of signal-plus-noise as a function of signal-to-noise ratio, thereby reducing the mean squared error in the output analog signal.