Title :
Subspace-based noise variance and SNR estimation for OFDM systems [mobile radio applications]
Author :
Xu, Xiaodong ; Jing, Ya ; Yu, Xiaohu
Author_Institution :
Nat. Mobile Commun. Res. Lab., Southeast Univ., Nanjing, China
Abstract :
Noise variance and hence signal to noise ratio (SNR) estimates are very important for the channel quality control in communication systems. Noting that in mobile communications the multipath time delays are slowly varying in time, in this paper we derive a subspace-based estimation method for orthogonal frequency division multiplexing (OFDM) systems, which is based on an eigenvector decomposition of the estimated channel correlation matrix. Simulation results show that the proposed estimator can obtain accurate real time measurements of the noise variance and SNR after an observation interval of about 20 OFDM symbols for various fading channels.
Keywords :
OFDM modulation; channel estimation; correlation methods; eigenvalues and eigenfunctions; fading channels; mobile radio; multipath channels; time-varying channels; OFDM systems; SNR estimation; channel correlation matrix estimation; channel quality control; eigenvector decomposition; fading channels; mobile communications; signal to noise ratio; subspace-based noise variance estimation; time varying multipath delays; Delay effects; Delay estimation; Frequency estimation; Land mobile radio; Matrix decomposition; Mobile communication; Noise measurement; OFDM; Quality control; Signal to noise ratio;
Conference_Titel :
Wireless Communications and Networking Conference, 2005 IEEE
Print_ISBN :
0-7803-8966-2
DOI :
10.1109/WCNC.2005.1424470
