Title :
Rate, sub-carrier, and power allocations for multi-carrier CDMA with LMMSE multiuser detections
Author :
Fu, Po-Wei ; Chen, Kwang-Cheng
Author_Institution :
Graduate Inst. of Commun. Eng., Nat. Taiwan Univ., Taipei
Abstract :
Allocations of physical transmission rate, sub-carrier, and power in MC-CDMA systems are proposed to minimize total uplink power consumptions for users of different data rate and bit-error-rate (BER) requirements with the receiver using linear minimum-mean-square-error (LMMSE) MUD. Based on multi-code (MC) and variable-spreading-length (VSL) strategies for multi-rate transmissions, we derive the discrete-rate transmission capacity of MC-CDMA and propose a simple admission control criterion for users of individual quality-of-service (QoS) demands. This criterion linearly relates the code length with the transmission rate and BER requirements of all users. An iterative power allocation algorithm is proposed after deciding all supportable transmission rates to allocate the sub-carrier power of each user and jointly solve the sub-carrier allocation problem. The results show that in either MC MC-CDMA or VSL MC-CDMA, the most power-efficient allocation is to distribute the power of each user over several sub-carriers of better quality and even concentrate on the best one, if it is exclusive
Keywords :
code division multiple access; encoding; error statistics; least mean squares methods; multiuser detection; power consumption; quality of service; receivers; resource allocation; telecommunication congestion control; BER; LMMSE multiuser detection; MC-CDMA system; MUD; QoS; admission control; bit-error-rate; linear minimum-mean-square-error; multicarrier code division multiple access; multicode strategy; power allocation; power consumption; quality-of-service; receiver; subcarrier allocation; transmission rate allocation; variable-spreading-length strategy; Bit error rate; Energy consumption; Frequency-selective fading channels; Iterative algorithms; Multiaccess communication; Multicarrier code division multiple access; Multiuser detection; Quality of service; Resource management; Streaming media;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2005. PIMRC 2005. IEEE 16th International Symposium on
Conference_Location :
Berlin
Print_ISBN :
9.7838007291e+012
DOI :
10.1109/PIMRC.2005.1651598
