An overview and characterization of multirate schemes for future-generation wireless systems

Several code-division multiple-access multirate modulation schemes are overviewed and characterized in terms of peak-to-average power ratio (PAV) and code pool required for a given multiplication factor of the basic information rate. A method of selecting and assigning codes for multiple rate, based on balanced incomplete block designs, is examined in detail. It is shown to have advantages in terms of a controlled PAV, economical use of codes, and error rate performance characteristics.