Patent ID: 7079592

Claim:
A complementary code keying (CCK) demodulation system utilized in demodulation equipment of WLAN, the CCK demodulation system comprising: a first-stage calculation apparatus used to perform a plurality of first-stage calculations with an input signal, and to output a plurality of first-stage calculation results, wherein the input signal has a communicative CCK codeword, and thirty-two CCK codewords of sixty-four CCK codewords are utilized in the plurality of first-stage calculations, and the plurality of first-stage calculation results are divided to eight groups, and each of the eight groups consists of at least one first-stage calculation result of the plurality of first-stage calculation results; a first decision module used to decide and compare the plurality of first-stage calculation results, and if a first-stage calculation result in a group of the eight groups is a maximum value of the plurality of first-stage calculation results and is greater than a maximum threshold, and meanwhile at least one other first-stage calculation result in the group is less than a minimum threshold, the communicative CCK codeword of the input signal is resolved by the first decision module in accordance with the maximum value, and if the maximum value of the plurality of first-stage calculation results is less than the maximum threshold and at least one of the plurality of first-stage calculation results is less than the minimum threshold, the first decision module outputs at least one activated signal; a second-stage calculation apparatus group used to receive the at least one activated signal and consists of a plurality of second-stage calculation apparatuses that constitute a first sub-apparatus group and a second sub-apparatus group, and according to the at least one activated signal, the first sub-apparatus group or the second sub-apparatus group is activated to perform at least one second-stage calculation with the input signal, and at least one second-stage calculation result is outputted, wherein another thirty-two CCK codewords of sixty-four CCK codewords are utilized in the at least one second-stage calculation; and a second decision module used to resolve the communicative CCK codeword of the input signal according to the least one second-stage calculation.