Title :
Capacity calculation in DS-CDMA systems supporting multi-class services
Author :
Lee, Seung Joon ; Lee, Hyeon Woo ; Sung, Dan Keun
Author_Institution :
Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea
Abstract :
We calculate the capacity of DS-CDMA systems supporting multi-class services with different transmission rates and bit error rates. Two techniques, a single-code scheme using a variable processing gain and a multi-code scheme, are considered to provide multi-rate services. The capacity is expressed by an inequality to which the number of accepted calls of each class should conform. The inequality is the necessary and sufficient condition satisfying the requirement of the bit energy-to-interference power spectral density ratio. The optimal received power is derived to cause the least interference to other signals while maintaining the acceptable bit energy-to-interference power spectral density ratio. Finally, the capacity is also derived in a dynamic multiple cell environment
Keywords :
cellular radio; channel capacity; code division multiple access; coding errors; error statistics; land mobile radio; pseudonoise codes; radiofrequency interference; spectral analysis; spread spectrum communication; DS-CDMA systems; PN codes; accepted calls; bit energy-to-interference power spectral density ratio; bit error rates; capacity calculation; dynamic multiple cell environment; inequality; multi-class services; multi-code scheme; necessary condition; optimal received power; single-code scheme; sufficient condition; transmission rates; variable processing gain; 3G mobile communication; Bit error rate; Bit rate; Frequency; Gain; Interference; Mobile communication; Multiaccess communication; Quality of service; Sufficient conditions;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 1997. Waves of the Year 2000. PIMRC '97., The 8th IEEE International Symposium on
Conference_Location :
Helsinki
Print_ISBN :
0-7803-3871-5
DOI :
10.1109/PIMRC.1997.630911