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Image compression has been a widely researched field for decades. Recently, there has been a growing interest in using basis selection algorithms for signal approximation and compression. Signal approximation using a linear combination of basis from an over-complete dictionary has proven to be an NP-hard problem. By selecting a smaller number of basis than the span of the signal, we achieve glossy compression in exchange for a small reconstruction error. For the past few decades orthogonal and biorthogonal complete dictionaries such as Discrete Cosine Transform (DCT) or wavelets were the dominant transform domain representations of signals. Over-complete dictionaries have been intensively studied and successfully applied to various application such as image de-noising, compression etc. The DCT and wavelet based compression methods suffer from blocking and ringing artefacts and also they are unable to capture the directional information. So, in this context an investigation has been made by using sparse coding method by Orthogonal Matching Pursuit (OMP) algorithm. In this proposed work, conventional DCT can be replaced by a set of trained dictionaries. For dictionary construction we have used a combination of DCT and Gabor basis and to encode the trained dictionary elements we have employed OMP algorithm. Experimental results demonstrate that the proposed method provides gains in Rate Distortion (RD) performance and improvements in perceptual quality.

For future broadband cellular communication networks wireless carriers has motivated the exploration of the under-utilized millimeter (mm-wave) frequency spectrum. The cellular mm wave propagation is densely populated in the world. It is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. This paper provides the overview of the recent worldwide activities for beyond 4G and 5G wireless standardization and technological aspects for millimeter wave communications. A complete characterization of the mm-wave link for next generation 5G mobile broadband remains elusive. The coverage, directionality and reliability of mm-wave communications will require new innovations in system design and communication technologies that are far from trivial. The transmission range and spatial selectivity's in the mm-wave bands especially in non line of sight channels can be increased by system design. So it require highly direction antennas and steerable antenna beams to compensate for the high propagation loss.

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