Low sequency W-CDMA codes lead to more economic WLL and infostation terminals
James G. Evans, B. R. Badrinath · International Journal of Communication Systems · 2000
Wireless local loop systems offer many advantages in providing voice and data services to an end user, unfortunately at high cost. Multi-rate wide-band code division modulation (W-CDMA) technology is proposed to serve both high and low data rate users. By an unusual assignment of codes, it is possible to reduce the cost of terminals for the strictly voice and low data rate user. An algorithm is presented to generate multi-rate long and short codes that are orthogonal over all symbol periods and ordered by sequency. Assigning the low sequency codes to the voice and low data rate users leads to a lower radio bandwidth and a lower chip rate. This allows the design of W-CDMA receivers requiring less processing. Therefore these receivers consume less power and cost less. Examples are presented where the effective chip rates are reduced as much as 8:1. Copyright © 2000 John Wiley & Sons, Ltd.