Enhancing BER performance limit of BCH and RS codes using multipath diversity

Modern wireless communication systems suffer from phase shifting and, more importantly, from interference caused by multipath propagation. Multipath propagation results in an antenna receiving two or more copies of the signal sequence sent from the same source but that has been delivered via different paths. Multipath components are treated as redundant copies of the original data sequence and are used to improve the performance of forward error correction (FEC) codes without extra redundancy, in order to improve data transmission reliability and increase the bit rate over the wireless communication channel. For a proof of concept Bose, Ray-Chaudhuri, and Hocquenghem (BCH) and Reed-Solomon (RS) codes have been used as FEC to compare their bit error rate (BER) performances. The results showed that the wireless multipath components significantly improve the performance of FEC. Furthermore, FEC codes with low error correction capability and employing the multipath phenomenon are enhanced to perform better than FEC codes which have a bit higher error correction capability and did not utilise the multipath. Consequently, the bit rate is increased, and communication reliability is improved without extra redundancy

Text image secret sharing with hiding based on color feature

The Secret Sharing is a scheme for sharing data into n pieces using (k, n) threshold method. Secret Sharing becomes an efficient method to ensure secure data transmission. Some visual cryptography techniques don’t guarantee security transmission because the secret information can be retrieved if the hackers obtain the number of shares. This study present a secret sharing method with hiding based on YCbCr color space. The proposed method is based on hiding the secret text file or image into a number of the cover image. The proposed method passes through three main steps: the first is to convert the secret text file or image and all cover images from RGB to YCbCr, the second step is to convert each color band to binary vector, then divide this band in the secret image into four-part, each part is appended with a binary vector of each cover image in variable locations, the third step is converting the color space from YCbCr to RGB color space and the generated shares, hidden with covers, are ready for transmission over the network. Even if the hackers get a piece of data or even all, they cannot retrieve the whole picture because they do not know where to hide the information. The results of the proposed scheme guarantee sending and receiving data of any length. The proposed method provides more security and reliability when compared with others. It hides an image of size (234x192) pixels with four covers. The MSE result is 3.12 and PSNR is 43.74. The proposed method shows good results, where the correlation between secret and retrieved images is strong ranging from (0.96 to 0.99). In the proposed method the reconstructed image quality is good, where original and reconstructed images Entropy are 7.224, 7.374 respectively

A CRYPTOGRAPHIC TECHNIQUE BASED ON AVL TREE ‫الـ‬ ‫شجرة‬ ‫على‬ ‫تعتمد‬ ‫جديد‬ ‫تشفير‬ ‫تقنية‬ AVL ‫اك‬ ‫البر‬ ‫نوري‬ ‫محمد‬ ‫علياء‬ ‫عبداهلل،‬ ‫نجم‬ ‫سرى‬ ‫جامعة‬ ‫العموم،‬ ‫كمية‬ ‫الحاسبات،‬ ‫قسم‬ ‫بغداد‬ ‫بغداد.‬ - ‫اق.‬ ‫العر‬ ‫الخالصة‬ ‫مكان‬ ‫من‬ ‫نق

Abstract Cryptography provides confidentiality and privacy by scrambling information. This paper presents a new cryptographic method using English letters frequencies and AVL tree to provide an increased level of confidence for exchanging information over networks especially internet which is insecure network. Experiment results of the proposed method provide better security than the classical methods depending on number of parts used to build the key in this method

Utilisation of multipath phenomenon to improve the performance of BCH and RS codes

In wireless communication, there exists a phenomenon known as ‘multipath’. This phenomenon is considered as a disadvantage because it causes interference. The multipath phenomenon results in an antenna receiving two or more signals from the same sent signal from different paths. This paper considers them as redundant copies of the transmitted data and utilises them to improve the performance of forward error correction (FEC) codes without extra redundancy, in order to improve data transmission reliability and increase the bit rate over wireless communication channels. The system was evaluated in bit error rate (BER) and used Bose, Ray-Chaudhuri and Hocquenghem (BCH) and Reed-Solomon (RS) codes as FEC. The results showed that the utilisation of the multipath improves the performance of FEC. Furthermore, the performance of FEC codes had t1 error correction capability and employed the multipath is better than FEC codes have t2 error correction capability and without the multipath, where t1 < t2. Consequently, the bit rate is increased, and communication reliability is improved without extra redundancy

Network coding/forward error correction code for multiple-input multiple-output wireless communication system

A reliable wireless communication channel is amongst the most important issues in a wireless network. Due to its nature, a reliable wireless communication channel is a challenge to provide. Wireless channel diversity is an efficient technique to achieve reliable transmission. Multi-antenna exploits spatial diversity as a method that has been proved to drastically increase channel capacity while keeping bit error rates (BER) near Shannon (lower bound) limits. Forward error correction code (FEC) or channel coding is an error control technique that is used to provide a time diversity to immunize data against errors over the noisy and unreliable wireless channel (Duman & Ghrayeb, 2007). The main idea behind FEC is that the transmitter encodes data by using error correction code (ECC) to add redundancy. This redundancy allows the receiver to detect and correct a specific number of bits in error - at a time - that may occur in the data stream. Multiple-input multiple-output (MIMO) systems combined with channel coding are shown to improve system BER and channel capacity performance in wireless communications. The combination is often referred to as a coded MIMO system. The aim of this research is to design or improve a FEC code algorithm for wireless communication network. This algorithm should be suitable to combine with MIMO system and be able to detect and correct the corrupted data in order to decrease the BER and increase wireless channel efficiency. The computational complexity and the data overhead will be used to measure the performance efficiency of the proposed algorithm