| 摘要 |
An improved method for computing sequence correlations utilizes pre-calculated look-up tables to reduce computational burdens. A sample sequence of symbols, such as a received sequence of symbols, is divided into a series of subblocks. A look-up table of combinational values is built for each subblock wherein the combinational values are arithmetic sums of the symbols in the subblock, either as received or negated. Preferably, the combinational values are computed in Gray code order so as to take advantage of bit-shifting and sign changes to lessen computational burdens. Correlation factors with respect to a known sequence of symbols are then calculated using the combinational values from these pre-calculated tables whenever possible. The correlation factors are then used in a known fashion to reach a correlation result. This method increase correlation computational efficiency in many situations, particularly for joint demodulation, code acquisition, and/or interference cancellation in wireless communications systems.
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