Space-time-frequency decorrelating decision-feedback multiuser detector over fast-fading multipath channels for synchronous DS-CDMA systems

2001-10-11
Ertug, O
Baykal, Buyurman
Unal, BS
RAKE receivers suffer degradation in performance under fast fading due to errors in channel state estimation. The wide-sense stationary uncorrelated scatterer channel model lends itself to time-frequency canonical representation, and provides additional diversity in the frequency axis. Using the joint spatial-multipath-Doppler diversity model based on this canonical representation, we propose a nonlinear space-time-frequency decorrelating decision-feedback multiuser detector for synchronous CDMA which utilizes decisions of the stronger users when forming the decisions for the weaker ones. Simulation results based on realistic fast-fading assumptions demonstrate that the proposed decorrelating decision-feedback multiuser detector promises substantially improved bit-error-rate performance compared to space-time-frequency decorrelating multiuser detector for the weaker users, while the error probability of the weakest user approaches the single-user bound as the interferers grow stronger. The proposed detector exhibits strong resistance to the near-far effect for all users and the time-complexity-per-bit is linear in the number of users.

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Citation Formats
O. Ertug, B. Baykal, and B. Unal, “Space-time-frequency decorrelating decision-feedback multiuser detector over fast-fading multipath channels for synchronous DS-CDMA systems,” presented at the 54th IEEE Vehicular Technology Conference (VTC 2001), ATLANTIC CITY, NJ, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53185.