Mobile Radio Channels Modeling in MATLAB

In this paper, a MATLAB based approach for mobile radio channels modeling is presented. Specifically, the paper introduces the basic concepts for modeling flat fading channels in MATLAB by means of user-defined m-files. Typical small-scale fading channel models are derived such as uncorrelated Rician fading channel and Rayleigh fading channel with Doppler shift. Further, simple and useful MATLAB constructions for approximation of cumulative distribution functions (CDFs) and probability density functions (PDFs) are also given. Finally, a MATLAB based Monte Carlo simulation example is presented, which comprises performance estimation of phase shift keying (PSK) signaling over a Rician fading channel

Convolutional/Single Parity Check Turbo Codes for Wireless Multimedia Communications

Error correction codes are widely used in digital communications to improve the Quality of Service. The Quality of Service is typically expressed in terms of maximum acceptable frame error rate and bit error rate. The key implementation issues for most powerful error correction codes are the complexity and overall encoding/decoding latency. In this paper, short-frame turbo product codes for real-time wireless multimedia communications are proposed. Performance of the proposed turbo codes is studied through simulations on an additive white Gaussian noise (AWGN) channel. The obtained results indicate that the performance of these codes is quite exceptional given their decoding complexity

Bose-Einstein condensates with F=1 and F=2. Reductions and soliton interactions of multi-component NLS models

We analyze a class of multicomponent nonlinear Schrodinger equations (MNLS) related to the symmetric BD.I-type symmetric spaces and their reductions. We briefly outline the direct and the inverse scattering method for the relevant Lax operators and the soliton solutions. We use the Zakharov-Shabat dressing method to obtain the two-soliton solution and analyze the soliton interactions of the MNLS equations and some of their reductions.Comment: SPIE UNO-09-UN101-19, SPIE Volume: 7501, (2009

Bulk correlation functions in 2D quantum gravity

We compute bulk 3- and 4-point tachyon correlators in the 2d Liouville gravity with non-rational matter central charge c<1, following and comparing two approaches. The continuous CFT approach exploits the action on the tachyons of the ground ring generators deformed by Liouville and matter ``screening charges''. A by-product general formula for the matter 3-point OPE structure constants is derived. We also consider a ``diagonal'' CFT of 2D quantum gravity, in which the degenerate fields are restricted to the diagonal of the semi-infinite Kac table. The discrete formulation of the theory is a generalization of the ADE string theories, in which the target space is the semi-infinite chain of points.Comment: 14 pages, 2 figure