Title

Performance Evaluation Of Fixed-Point Least Mean Square Adaptive Algorithm Used For Cancellation Of I/Q Channels Mismatch In Direct Conversion Wireless Receiver

Keywords

Adaptive and Fixed-Point Numbers; Direct Conversion Receiver; Fixed Point Least Mean Square; I/Q Mismatch

Abstract

Direct Conversion Receiver (DCR) is a good solution for small, low power devices but they have I/Q mismatch associated with it. The I/Q mismatch severely degrades the performance of DCR. Adaptive solutions using Least-Mean-Square (LMS) algorithm has been proposed and successfully implemented to over come this mismatch. Floating-point solution by using LMS has been proposed before. In this paper, a fixed-point approach for implementing LMS has been proposed because of the advantages offered like reduced hardware cost, size and complexity. In the Quadrature Phase Shift Keying (QPSK) receivers, the imbalance caused due to the mismatch in low pass filter (LPF) and local oscillator (LO) are considered for the simulation. Fixed Point Least Mean Square (FPLMS) algorithm is implemented successfully to over come this mismatch. This method has a near optimum solution if the proper word lengths are used for the fixed-point implementation. The word lengths have to be mapped taking in consideration the vector that is to be mapped. By mapping individual vectors according to the range and using a good precision, we get results equal to that obtained by using a floating-point implementation.

Publication Date

12-1-2005

Publication Title

WMSCI 2005 - The 9th World Multi-Conference on Systemics, Cybernetics and Informatics, Proceedings

Volume

5

Number of Pages

181-185

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

Socpus ID

84867341798 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84867341798

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