Inlämning av Examensarbete / Submission of Thesis

Daxious Mengistu Wendemu MEE10:63, pp. 45. ING/School of Engineering, 2010.

The work

Författare / Author: Daxious Mengistu Wendemu
Titel / Title: Digital Methods for Reduction of IQ Imbalance in OFDM Systems
Översatt titel / Translated title: Digital Methods for Reduction of IQ Imbalance in OFDM Systems
Abstrakt Abstract:

Orthogonal frequency division multiplexing (OFDM) based systems are susceptible to radio front end induced impairments. These impairments caused by as a consequence of imbalances in the In-phase (I) and Quadrature-phase (Q) branches. IQ imbalances are worries to be addressed for the Superhetrodyne and the zero IF architectures in analog domain.
The zero-IF architecture is a prospective solution to include multiple RF standards while making straightforward the design and dropping overall costs. However in the practical implementation of the zero-IF receiver architecture IQ imbalance has been recognized as one of the most serious concerns.
At the receiver the expected working signal to noise ratio (SNR) can be affected heavily by the presence of IQ imbalance. As a result of this imbalance the data rates and the supported constellation are also affected.
In this thesis the effect of IQ imbalance on OFDM receivers is considered and digital methods are proposed to tackle the effect of IQ imbalance and enhance the operating signal to noise ratio (SNR). The methods are the least square (LS) and the least mean algorithm (LMS). With the help of computer simulation we are going to study the performance of both reduction techniques. The bit error rate (BER) Verses signal to noise ratio (SNR) result could indicate the proposed techniques provide sufficient improved performance.

Ämnesord / Subject: Telekommunikation - Telecommunications
Signalbehandling - Signal Processing
Elektroteknik - Electrotechnology
Nyckelord / Keywords: IQ imbalance, least square (LS), least mean algorithm (LMS), OFDM

Publication info

Dokument id / Document id:
Program:/ Programme Electrical Engineering with emphasis on Telecommunication
Registreringsdatum / Date of registration: 07/08/2010
Uppsatstyp / Type of thesis: Masterarbete/Master's Thesis (120 credits)


Handledare / Supervisor: Kristian Nilsson
Examinator / Examiner: Jörgen Nordberg
Organisation / Organisation: Blekinge Institute of Technology
Institution / School: ING/School of Engineering

+46 455 38 50 00

Files & Access

Bifogad uppsats fil(er) / Files attached: final_thesis_report.pdf (1244 kB, öppnas i nytt fönster)