Title :
Downlink channel decorrelation in CDMA systems with long codes
Author :
Werner, Stefan ; Lilleberg, Jorma
Author_Institution :
Lab. of Telecommun. Technol., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
We develop linear detectors suitable for a code division multiple access (CDMA) mobile receiver using long codes. The special signal structure in the downlink transmission is exploited to obtain a simple detection rule. A least-squares (LS) detector, a best linear unbiased estimator (BLUE) detector, and a linear minimum mean-square error (LMMSE) detector are derived. For the LMMSE detector we consider an adaptive implementation. The results show that improvement can be achieved using the proposed detectors compared with that of the conventional RAKE receiver
Keywords :
Hadamard codes; adaptive signal detection; code division multiple access; decorrelation; land mobile radio; least mean squares methods; least squares approximations; multipath channels; multiuser channels; parameter estimation; radio links; radio receivers; spread spectrum communication; BLUE detector; CDMA systems; RAKE receiver; Walsh-Hadamard codes; adaptive LMMSE detector; best linear unbiased estimator detector; code division multiple access; detection rule; downlink channel decorrelation; downlink transmission; least-squares detector; linear detectors; linear minimum mean-square error; long scrambling codes; mobile receiver; multipath channel; signal structure; spreading codes; Covariance matrix; Decorrelation; Detectors; Downlink; Interference suppression; Laboratories; Multiaccess communication; Multipath channels; Multiple access interference; RAKE receivers;
Conference_Titel :
Vehicular Technology Conference, 1999 IEEE 49th
Conference_Location :
Houston, TX
Print_ISBN :
0-7803-5565-2
DOI :
10.1109/VETEC.1999.780668
