Information and System Group

March 2014

 1 2014-03-11 Improved Successive Cancellation Decoding of Polar Codes Jeong-Min Ryu  (pdf)
A new decoding algorithm called the successive cancellation hybrid (SCH) is proposed. This proposed algorithm can provide a flexible configuration when the time and space complexities are limited. Furthermore, a pruning technique is also proposed to lower the complexity by reducing unnecessary path searching operations. Performance and complexity analysis based on simulations shows that under proper configurations, all the three improved successive cancellation (ISC) decoding algorithms can approach the performance of the maximum likelihood (ML) decoding but with acceptable complexity.
2 2014-03-25 On some multiple integrals involving determinants Oliver (DOC)
This paper introduces a way to evaluate an N-dimensional integration whose integrand is a determinant of a matrix. This approach in this paper is general in nature and in particular, it is useful to derive eigenvalue distributions of Wishart matrices.
3 2014-04-01 Identifying Wireless User via Transmitter Imperfections JuSung Kang (DOC)
In this papers, the authors detail a first step toward a model based approach, which uses statistical models of RF transmitter components that are amenable for analysis. Algorithms based on statistical signal processing methods are developed to exploit non-linearities of wireless transmitters for the purpose of user identification in wireless systems. The decision rules are derived and their performance is analyzed. Results show that the proposed identification methods can be effective, even for short data records and relatively low signal-to-noise ratios.
4 2014-05-13 Compressed Sensing Detector Design for Space Shift Keying in MIMO Systems Haeung Choi (pdf)
A promising communication method, Massive MIMO is the large-scale multiple-input multiple-output(MIMO) technique which can achieve maximum diversity gain and large spatial multiplexing gain. However, massive MIMO also has many challenging problems such as heavy interference, expensive hardware cost, and large complexity of receiver. In spite of using generalized spatial shift keying(GSSK), which is one of methods to reduce the complexity of detection, the high complexity of optimal ML detector still becomes an obstacle. Author purposed a new (G)SSK detector applying the compressive sensing(CS) theory. Their detector, named normalized compressive sensing(NCS) (G)SSK detector can achieve considerable performance with low complexity compared with the optimal ML detector.
4 2014-05-27 Outage Probability of Cognitive Relay Networks with Interference Constraints Zafar Iqbal (doc)
The authors evaluate the outage probability of cognitive relay networks with cooperation between secondary users based on the underlay approach, while adhering to the interference constraint on the primary user. A relay selection criterion, suitable for cognitive relay networks, is provided, and using it, they derive the outage probability. It is shown that the outage probability of cognitive relay networks is higher than that of conventional relay networks due to the interference constraint. In addition, the outage probability is affected by the distance ratio of the interference link (between the secondary transmitter and the primary receiver) to the relaying link (between the secondary transmitter and the secondary receiver). They also prove that cognitive relay networks achieve the same full selection diversity order as conventional relay networks, and that the decrease in outage probability achieved by increasing the selection diversity (the number of relays) is not less than that in conventional relay networks.