Paper Info
Title
Low Complexity CFO Compensation in Uplink OFDMA Systems With Receiver Windowing
Abstract
Orthogonal frequency division multiple access (OFDMA) systems in the uplink suffer from multiple access interference (MAI) due to their high sensitivity to frequency misalignments between different users. In this paper, we propose the application of time domain receiver windowing methods to confine the leakage caused by multiple carrier frequency offsets (CFOs) to a few neighboring subcarriers with almost no additional computational burden. The CFO effects can be translated into a linear system of equations with a coefficient matrix that is called interference matrix. As a result of receiver windowing, we can approximate the interference matrix with a quasi-banded one by neglecting its small elements outside a certain bandwidth. This allows us to propose a class of low complexity CFO compensation techniques. These techniques are applicable to the generalized subcarrier allocation scheme (G-CAS). The complexity reduction in the proposed solutions is substantial when compared to the existing ones in the literature. It is worth mentioning that this substantial complexity reduction is achieved in expense of some bandwidth efficiency loss. Hence, there exists a tradeoff between bandwidth efficiency and complexity. Solutions based on both zero forcing (ZF) and minimum mean squared error (MMSE) criteria are proposed and compared. Simulation results demonstrating the effectiveness of the proposed algorithms in approaching the optimal performance are also presented.
Year
DOI
Venue
2015
10.1109/TSP.2015.2413379
Signal Processing, IEEE Transactions  
Keywords
Field
DocType
cfo,ici,mai,mmse,ofdma,synchronization,uplink,zf,ofdm,resource management,bandwidth,ofdm modulation,approximation theory,interference
Subcarrier,Coefficient matrix,Control theory,Minimum mean square error,Orthogonal frequency-division multiple access,Reduction (complexity),Bandwidth (signal processing),Spectral efficiency,Mathematics,Orthogonal frequency-division multiplexing
Journal
Volume
Issue
ISSN
63
10
1053-587X
Citations 
PageRank 
References 
5
0.43
19
Authors
4
Name
Order
Citations
PageRank
Arman Farhang113114.01
Nicola Marchetti219233.90
Linda E. Doyle330434.70
Behrouz Farhang-Boroujeny497284.30