Title :
Efficient Scheduling for Delay Constrained Multi-Rate CDMA Systems
Author :
Chen, Min ; Oh, Changyoon ; Yener, Aylin
Author_Institution :
Electr. Eng. Dept., Pennsylvania State Univ., University Park, PA
Abstract :
We consider efficient scheduling for a delay constrained multi-rate CDMA system. We first find the optimum schedule for CDMA systems without transmit diversity (TD), that minimizes the average transmission energy per bit while maintaining the short term average throughput for each user in the system. We observe that the specifics of the scheduling problem enables it polynomially solvable. Next, we consider the case when mobile devices are capable of employing two antennas and use Alamouti scheme to achieve TD. We observe that our proposed scheduling protocol can be extended to the system with TD with a modest sacrifice in performance and significant saving in computational complexity, as compared to the optimum scheduler. Simulation results are presented to demonstrate the performance of the proposed scheduling protocols, and the considerable energy savings they provide with respect to the TDMA-type scheduling
Keywords :
code division multiple access; diversity reception; protocols; scheduling; time division multiple access; Alamouti scheme; TDMA; antenna; code division multiple access; mobile device; multirate CDMA system; scheduling protocol; time division multiple access; transmit diversity; Computational complexity; Computational modeling; Delay; Mobile antennas; Mobile computing; Multiaccess communication; Polynomials; Processor scheduling; Protocols; Throughput;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2006 IEEE Ninth International Symposium on
Conference_Location :
Manaus-Amazon
Print_ISBN :
0-7803-9779-7
Electronic_ISBN :
0-7803-9780-0
DOI :
10.1109/ISSSTA.2006.311797