Gravitational Search Algorithm for Low Complexity Carrier Frequency Offset Estimation in Uplink OFDMA Systems
نویسندگان
چکیده
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. Moreover, carrier frequency offset (CFO) is a major factor that degrades performance of the OFDMA system. As the maximumlikelihood (ML) estimator is impractical in this context, we introduce a family of suboptimal estimators with the aim of exhibiting an attractive tradeoff between performance and complexity. 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. In this paper, we propose a new approach called gravitational search algorithm (GSA), for CFO estimation. Performance and complexity comparisons are provided, along with numerical results to illustrate the effectiveness of the proposed method. Simulation results demonstrating the effectiveness of the proposed algorithms in approaching the optimal performance are also presented. KeywordsOFDMA; gravitational search algorithm; carrier frequency offset, ML
منابع مشابه
PSO and ABC based Novel Carrier Frequency Offset Estimation Techniques for Wi-MAX Uplink Transmissions
Carrier frequency offset (CFO) estimation is a challenging task in Wi-MAX uplink as it uses orthogonal frequency division multiple access (OFDMA) which demands extremely accurate frequency synchronization. In OFDMA uplink, each user may experience a different CFO relative to the base station reference carrier and the estimation of them turn out to be a multiple parameter estimation problem. In ...
متن کاملA reduced complexity scheme for carrier frequency synchronization in uplink 802.16e OFDMA
Synchronization of the carrier frequency offset (CFO) in the uplink of OFDMA systems is a complex task because each user presents a different CFO. It is performed in two stages: estimation and compensation. Although a few existing schemes already achieve good performance in terms of bit error rate (BER), all of them perform huge amounts of operations, specially during estimation, thus leading t...
متن کاملAP Line Search-based Joint Estimation of Carrier Frequency Offset and Channel Response in Uplink OFDMA
متن کامل
Analysis of Iterative ICI Cancellation Algorithm for Uplink OFDMA Systems with Carrier-Frequency Offset
In orthogonal frequency-division multiplex access (OFDMA) uplink, the carrier-frequency offsets (CFOs) between the multiple transmitters and the receiver introduce inter-carrier interference (ICI) and severely degrade the performance. In this paper, based on the perfect estimation of each user’s CFO, we propose two low-complexity iterative algorithms to cancel ICI due to CFOs, which are denoted...
متن کاملSAGE based iterative receiver for joint synchronization and channel estimation in uplink MIMO-OFDMA systems
A new Turbo iterative receiver structure is proposed for the uplink multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA) systems. The space-alternating generalized expectation-maximization (SAGE) algorithm is naturally embedded in the framework of iterative receiver to perform synchronization and detection using the Turbo detector outputs. In each iteration,...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2016