Performance and Optimization of Multistage Partial Parallel Interference Cancellation for Wideband CDMA Systems in Multipath Fading Channels
| Autor: | Li Zhong-ling, Li Shaoqian, Hu Cheng-hua, Tang Youxi |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Multipath interference
Computer Networks and Communications Code division multiple access Computer science Aerospace Engineering Interference (wave propagation) Spread spectrum symbols.namesake Signal-to-noise ratio Additive white Gaussian noise Single antenna interference cancellation Automotive Engineering Electronic engineering Bit error rate symbols Electrical and Electronic Engineering Wideband Multipath propagation Computer Science::Information Theory Communication channel Rayleigh fading |
| Zdroj: | IEEE Transactions on Vehicular Technology. 55:1137-1158 |
| ISSN: | 0018-9545 |
| Popis: | In this paper, a closed-form bit error rate (BER) of hard-decision multistage partial parallel interference cancellation (PPIC) having perfect and imperfect channel estimation for complex spreading code-division multiple access (CDMA) over multipath Rayleigh channels was derived. The effects of receiving BER, power ratio of pilot to data channels, multiple-access interference (MAI) and multipath interference, additive white Gaussian noise, and other factors affecting channel estimation error are analyzed. The expression determining the optimal interference cancellation weight at path level for PPIC is first derived. Then, the oscillatory behavior of user-level-optimized PIC and the convergence of perfect channel estimation PIC and path-level-optimized PIC are validated. Results indicate that all factors determining the optimal weight certainly affect the BER performance of PPIC and that the lower BER limit of multistage PPIC depends on the adjustable factors, which include power ratio, observation length, and signal-to-noise ratio, and an unchangeable factor, i.e., number of users. In addition, the variance of MAI for complex spreading sequence is obtained, and the analytical expression can also be employed to predict the performance of multicode CDMA |
| Databáze: | OpenAIRE |
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