摘要 |
A hardware-efficient data receiver in which the receiver digital baseband signal samples relate to the bits in the transmission signal. For each sample, a metric calculator calculates an input data element (metric) for the soft decision decoder in the receiver. The metric is a binary word of whose most significant bit (gross bit) indicates the most likely value ('0' or '1') of a bit in the transmission signal. The other bits of the metric (reliability bits) express the reliability of this gross bit. The metric calculator has a monotonous transition function with equidistant steps between two extreme metric values (all metric bits are '0' or '1'). According to this transition function, the metric value varies as a function of the digital baseband signal sample value in a range bounded by two saturation values. The number of different sample values in this range, including the saturation values, is two to the power of an integer. Within this range, the reliability bits may readily be derived from a selected number of bits in the binary representation of a digital baseband sample.
|