| 摘要 |
A receiver for data encoded as a series of symbols, each including a plurality of components such as the I and Q components of 16-QAM symbols or other multi-value multi-phase system. Each component denotes values for a plurality of bits. Probability calculation circuits 111-1 through 111-16 use the values of the components constituting each received symbol to calculate the probability that each one of the possible symbols was transmitted and received. Metric calculation circuits 112-1 through 112-4 calculate a bit metric for each bit denoted by the symbol. The bit metric represents the probability that the bit having a specified value was transmitted. The bit metric may be calculated by adding the probabilities calculated by the probability calculation for those possible symbols having a component denoting the specified value of the bit. For example, the sum of the probabilities of all symbols denoting a first bit value of zero gives the probability that a zero bit value was transmitted and received. The data represented by the symbols may represent data encoded by a convolutional code, and the bit metrics may be supplied to a decoder such as a Viterbi decoder.
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