| 摘要 |
A spread spectrum product encoding method keeping a predetermined amplitude of a transmission signal in a code division multiple access communication system is provided to encode data bits to keep an amplitude of linear combination of orthogonal codes constantly, thereby preventing orthogonal damages due to level clipping. A hierarchic constant amplitude basis encoding device comprises a level converter(710), a residual bit generating unit(720), a basis encoding multiplicator(730), a basis encoding digital adding up unit(740) and a normalization unit(750). The basis encoding digital adding up unit adds up multiplication results of the basis encoding multiplicator to generate four chip signals having constant amplitudes. The normalization unit normalizes output of the digital adding up unit to generate four outputs of constant amplitude chips which have (+1) or (-1) values. |
