CCK modulation
CCK is a coded modulation technique that designs spread spectrum, channel coding, and modulation as a whole to improve the overall performance of the system. The CCK code is defined by a set of 256 8-chip codewords. The codeword is composed of the following equation [2]:
Figures 2 and 3 demonstrate the performance of CCK under AWGN channel and Rayleigh fading channel respectively. The decoding method under Rayleigh fading channel adopts the maximum likelihood hard decision, and the fading rate is f = Tsfd = 0.04. As can be seen from the figure, in the AWGN channel Next, the performance of large number logic decoding is slightly worse than that of maximum likelihood decoding. In fading channels, the performance of CCK with channel interleaving is better than that without channel interleaving, but the difference is not too large because the interleaving depth in simulation not big enough. On the other hand, under multipath channels, the performance is better than single-path channels, because the ideal channel estimation is assumed in the simulation, the impact of multipath channels is reflected in faster fading, and the interleaving depth is the same, so multipath The interleaving is more sufficient under the channel, so the performance is better.
Analysis of code modulation performance of concatenated LDPC codes and CCK
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