Application of Convolution Code in CCK Modulation Technology

Adopted by IEEE802.11b standard as the high speed expanding scheme, CCK modulation technology performs well in error probability with high signal noise ratio. However, the CCK system’s error probability soars when SNR is comparably low or the number of users in the same channel increases suddenly. Based on CCK algorithm and convolution code’s structure, this paper analyzed code parameters’ influence on error probability and proposed a channel coding scheme suitable for CCK modulation: convolution code （2,1,7）with 3bit soft decision decoding. Simulation Results demonstrated that system performance is greatly improved when SNR is upon 1.3dB and 2dB’s additional coding gain is attained compared with hard decision decoding.