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 . the 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 .