Downlink Site Diversity with Frequency-Domain Equalization for a DS-CDMA Cellular System

Author

Sato, Hirotaka ; Tomeba, Hiromichi ; Takeda, Kazuaki ; Adachi, Fumiyuki

Author_Institution

Dept. of Electr. & Commun. Eng., Tohoku Univ.

fYear

2006

fDate

Oct. 2006

Firstpage

1

Lastpage

5

Abstract

In DS-CDMA high speed wireless signal transmissions, the bit error rate (BER) performance with coherent rake combining degrades due to inter-path interference (IPI) caused by a severe frequency-selective fading. The use of frequency-domain equalization (FDE) can significantly improve the BER performance. However, the local average received signal power slowly varies due to path loss and shadowing loss according to the movement of a mobile user. This variation degrades the link capacity particularly when the user is located close to the cell edge. To improve the link capacity, the well-known site diversity can be used in conjunction with FDE. In this paper, we present downlink site diversity with FDE for a DS-CDMA cellular system and derive the MMSE weight for site diversity combining. The downlink capacity is evaluated by computer simulation and compared to the case with coherent rake combining. Then it is shown that the link capacity with FDE is better than that with coherent rake combining

Keywords

cellular radio; code division multiple access; diversity reception; equalisers; error statistics; fading channels; frequency-domain analysis; least mean squares methods; spread spectrum communication; BER; DS-CDMA cellular system; FDE; IPI; MMSE; bit error rate; coherent rake combining; direct sequence code division multiple access; downlink site diversity combining; frequency-domain equalization; frequency-selective fading; interpath interference; link capacity; minimum mean square error methods; wireless signal transmission; Bit error rate; Computer simulation; Degradation; Diversity reception; Downlink; Fading; Frequency; Interference; Multiaccess communication; Shadow mapping;

fLanguage

English

Publisher

ieee

Conference_Titel

Communication systems, 2006. ICCS 2006. 10th IEEE Singapore International Conference on

Conference_Location

Singapore

Print_ISBN

1-4244-0411-8

Electronic_ISBN

1-4244-0411-8

Type

conf

DOI

10.1109/ICCS.2006.301489

Filename

4085784