Open AccessPilot pollution interference cancellation in CDMA systems
Author(s) -
ElSaid Mostafa M.,
Kumar Anup,
Elmaghraby Adel S.
Publication year - 2003
Publication title -
wireless communications and mobile computing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.42
H-Index - 64
eISSN - 1530-8677
pISSN - 1530-8669
DOI - 10.1002/wcm.154
Subject(s) - computer science , rake receiver , multipath propagation , interference (communication) , rake , orthogonality , code division multiple access , telecommunications , signal (programming language) , single antenna interference cancellation , cdma spectral efficiency , energy (signal processing) , electronic engineering , decoding methods , channel (broadcasting) , engineering , mechanical engineering , statistics , mathematics , programming language , geometry
In CDMA systems, existence of large number of equally strong pilot signals is not desirable. As a consequence, this would create pilot pollution interference (PPI). Additionally, the limited number of fingers in the RAKE receiver adds a different dimension to the problem. The PPI has the influence of overloading the mobile station's RAKE receiver with excessive amount of signaling on the dedicated control channels. Therefore, the pilot signal's orthogonality erodes dramatically, and the system suffers from dropping of ongoing calls, blocking of originating fresh calls and decrease in the system capacity. In this paper, we demonstrate the power of using a novel multi‐carrier chip shaping to alleviate the impact of the PPI. Consequently, the mobile's RAKE receiver will have the capability to perform frequency diversity rather than multipath diversity. This will make efficient use of the received signal energy in the frequency domain and boost the performance of the system. Simulation studies have been carried out to verify the appropriateness of the proposed approach and we have obtained very promising results. Copyright © 2003 John Wiley & Sons, Ltd.