Paper Info
Title
Channel coding for progressive images in a 2-D time-frequency OFDM block with channel estimation errors.
Abstract
Coding and diversity are very effective techniques for improving transmission reliability in a mobile wireless environment. The use of diversity is particularly important for multimedia communications over fading channels. In this work, we study the transmission of progressive image bitstreams using channel coding in a 2-D time-frequency resource block in an OFDM network, employing time and frequency diversities simultaneously. In particular, in the frequency domain, based on the order of diversity and the correlation of individual subcarriers, we construct symmetric n -channel FEC-based multiple descriptions using channel erasure codes combined with embedded image coding. In the time domain, a concatenation of RCPC codes and CRC codes is employed to protect individual descriptions. We consider the physical channel conditions arising from various coherence bandwidths and coherence times, leading to a range of orders of diversities available in the time and frequency domains. We investigate the effects of different error patterns on the delivered image quality due to various fade rates. We also study the tradeoffs and compare the relative effectiveness associated with the use of erasure codes in the frequency domain and convolutional codes in the time domain under different physical environments. Both the effects of intercarrier interference and channel estimation errors are included in our study. Specifically, the effects of channel estimation errors, frequency selectivity and the rate of the channel variations are taken into consideration for the construction of the 2-D time-frequency block. We provide results showing the gain that the proposed model achieves compared to a system without temporal coding. In one example, for a system experiencing flat fading, low Doppler, and imperfect CSI, we find that the increase in PSNR compared to a system without time diversity is as much as 9.4 dB.
Year
DOI
Venue
2009
10.1109/TIP.2009.2026676
IEEE Transactions on Image Processing
Keywords
Field
DocType
channel variation,frequency selectivity,channel estimation error,progressive image,2-d time-frequency ofdm block,time domain,physical channel condition,embedded image coding,time diversity,coherence time,channel erasure code,frequency domain,ofdm,concatenation,parameter estimation,frequency domain analysis,forward error correction,orthogonal frequency division multiplexing,coherence,engineering,ofdm modulation,fading channel,convolutional code,frequency diversity,time frequency analysis,channel coding,convolutional codes,image processing,mobile communication,time frequency,fading,subcarrier,image quality,multiple description coding,erasure code
Forward error correction,Convolutional code,Telecommunications,Fading,Artificial intelligence,Erasure code,Time diversity,Diversity scheme,Pattern recognition,Algorithm,Binary erasure channel,Mathematics,Orthogonal frequency-division multiplexing
Journal
Volume
Issue
ISSN
18
11
1941-0042
Citations 
PageRank 
References 
16
0.76
26
Authors
4
Name
Order
Citations
PageRank
Laura Toni118615.22
Yee Sin Chan21198.39
Pamela C. Cosman375877.83
Laurence B. Milstein41129280.97