Methods and apparatus for code division multiple access communication using code book that provides reduced peak-to-average power ratio

摘要

A method and apparatus are provided for generating a code book for use in a CDMA system. The code book comprises of a plurality of vectors that are used to encode user data. An amplitude and polarity for each vector in the code book are selected to provide a reduced peak-to-average power ratio. The amplitude values can be selected to provide a reduced peak-to-average power ratio while maintaining a desired average energy per chip. The desired energy per chip can be based on the energy per chip of a CDMA system having a lower order spreading factor. Performance can be further improved by employing a first code book under a first signal-to-noise ratio condition and a second code book under a second signal-to-noise ratio condition.