Yuan Y.,Carnegie Mellon University |
Zuo Z.,Portland State University |
Guan Y.,Wireless Research Institute |
Chen X.,Wireless Research Institute |
And 4 more authors.
IEEE Communications Magazine | Year: 2014
Various technologies in LTE/LTE-Advanced have significantly improved the data throughput of 4G systems. However, the coverage of LTE networks, a very important performance metric to operators, receives relatively less attention. In this article we describe the motivations of LTE coverage enhancements from several aspects. Through link budget analysis, the limiting link and channels are identified. Then potential solutions to LTE coverage enhancements are discussed in a comprehensive manner, with the focus on schemes of specification impact. This article provides insights on how to design practical schemes to improve the coverage of LTE/LTE-Advanced systems. © 2014 IEEE.
Wu J.,Xidian University |
Wu J.,Hanyang University |
Xing Y.,Wireless Research Institute |
Jeong J.,Hanyang University |
And 2 more authors.
Journal of Applied Remote Sensing | Year: 2010
In this paper, we propose an embedded satellite image compression method using Weighted ZeroBlock Coding (WZBC) and optimal sorting. In order to reduce average codeword length, Set Partition Embedded block (SPECK) and Embedded ZeroBlock Coder (EZBC) both encode significant block-sets with fixed-length bits, while WZBC assigns different-length bits to encode block-sets which contain different numbers of significant subblocks. In view of the context correlation among coefficients/blocks, WZBC employs a weight context to optimize the scanning order of the significance testing and the ratedistortion performance. Experimental results show that the proposed WZBC in binary coding mode provides excellent coding performance compared with those of SPECK and Set Partitioning In Hierarchical Trees (SPIHT) which use arithmetic coding, and can even closely approach that of JPEG2000. When arithmetic coding is extensively used, the proposed method has clear advantages. © 2010 Society of Photo-Optical Instrumentation Engineers.