Joint Estimation of Carrier Frequency Offset, Sampling Frequency Offset and Channel Response for OFDM Systems
Date Issued
2009
Date
2009
Author(s)
Huang, Yu-Xuan
Abstract
Orthogonal frequency division multiplexing (OFDM) systems have been widely used and standardized for broadband wireless and wired communication systems. Due to cost, package size and power consumption, direct-conversion radio frequency (RF) receivers are popularly adopted to demodulate OFDM signals recently. For siliconmplementation, The devices can suffer from various mismatches between transmitters and receivers. Unfortunately, OFDM systems areery sensitive to these distortions or synchronization errors such as Carrier frequency offset (CFO) and sampling frequency offset (SFO). These synchronization errors at the receiver lead to intolerable inter-carrier interference (ICI). Hence we must get anccurate estimation of the CFO and SFO and compensate them properly at the receiver.n this thesis, the effects of CFO and SFO on OFDM systems are first studied. We discussed that joint influence of SFO and CFO in frequency domain. Then several estimation methods of these parameters are proposed. Firstly we propose a time domain method based on Taylor expansion for joint estimation of CFO, SFO and channel response by using a repeated training sequences. Secondly wentroduce a frequency-domain method that can jointly estimate these parameters by using pilots (instead of training sequences). A low cost iterative algorithm is proposed to solve the joint estimation of SFO and CFO in the frequency domain. Simulation results show thathe performance of the proposed methods is good.
Subjects
OFDM System
Carrier Frequency Offset
Sampling Frequency Offset
Channel Response
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R96942035-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):aa843956afea1bf491645868924b612e