A LINEAR PRECODING STRATEGY BASED ON PARTICLE SWARM OPTIMIZATION IN MULTICELL COOPERATIVE TRANSMISSION

An optimal linear precoding scheme based on Particle Swarm Optimization(PSO),which aims to maximize the system capacity of the cooperative transmission in the downlink channel,is proposed for a multicell multiuser single input single output system.With such a scheme,the optimal precoding vector could be easily searched for each user according to a simplified objective function.Simulation results show that the proposed scheme can obtain larger average spectrum efficiency and a better Bit Error Rate(BER) performance than Zero Forcing(ZF) and Minimum Mean Square Error(MMSE) algorithm.

A PREDICTOR-CORRECTOR INTERIOR-POINT ALGORITHM FOR CONVEX QUADRATIC PROGRAMMING

The simplified Newton method, at the expense of fast convergence, reduces the work required by Newton method by reusing the initial Jacobian matrix. The composite Newton method attempts to balance the trade-off between expense and fast convergence by composing one Newton step with one simplified Newton step. Recently, Mehrotra suggested a predictor-corrector variant of primal-dual interior point method for linear programming. It is currently the interiorpoint method of the choice for linear programming. In this work we propose a predictor-corrector interior-point algorithm for convex quadratic programming. It is proved that the algorithm is equivalent to a level-1 perturbed composite Newton method. Computations in the algorithm do not require that the initial primal and dual points be feasible. Numerical experiments are made.

Study on Porous Silicon with P-N Junction Sensor for Humidity Measurement

Porous materials used for humidity sensing have been commercialized.In this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are studied.PNJPS is made by electro-chemical anodic etched method from silicon wafers with P-N junctions.Its porous structure is verified by scanning electronic micrograph. Experiments also show that PNJPS has high sensitivity,short response time (less than 30 seconds),and long-term stability.

On Network MIMO:Base Station Coordination

"Network MIMO" is implemented to eliminate intercell interference and improve spectral efficiency.Several system models are introduced here and synchronous and asynchronous interference are considered.This paper also has a look on the algorithms on the uplink decoding and downlink precoding in network MIMO with base station coordination.Two levels of base station coordination and cellular backhaul are presented,too.

Set (k, n)-Exactly covering problem

With the (k,n) -threshold scheme of secret sharing in the field of information security technology asan application background,the concept of set ( k,n)-exact cover is presented in this paper.It is a modificationof the original concept of set covering problem.It is also different from the concept of exact coverdefined by J.E.Hopcroft.Some properties of ( k,n) -exact cover are investigated;a sufficient conditionfor a set to be ( k,n ) -exactly coverable is given.It follows that a feasible assignment scheme of a set forthe (k,n) -exact cover is obtained if this set satisfies the sufficient condition.

Irregular Segmented Region Compression Coding Based on Pulse Coupled Neural Network

An irregular segmented region coding algorithm based on pulse coupled neural network(PCNN) is presented. PCNN has the property of pulse-coupled and changeable threshold, through which these adjacent pixels with approximate gray values can be activated simultaneously. One can draw a conclusion that PCNN has the advantage of realizing the regional segmentation, and the details of original image can be achieved by the parameter adjustment of segmented images, and at the same time, the trivial segmented regions can be avoided. For the better approximation of irregular segmented regions, the Gram-Schmidt method, by which a group of orthonormal basis functions is constructed from a group of linear independent initial base functions, is adopted. Because of the orthonormal reconstructing method, the quality of reconstructed image can be greatly improved and the progressive image transmission will also be possible.

Novel sol-gel material for fabrication of a long period waveguide grating filter as a precise thermometer

A new kind of organic-inorganic hybrid HfO 2/SiO 2 sol-gel material with a large thermo-optic coefficient and a wide linear tunable temperature range has been developed for fabrication of a long period waveguide grating (LPWG) filter,whose parameters were optimized and designed by using finite difference time domain (FDTD) simulations.The LPWG filter,a periodic rectangle-corrugated grating structure,was easily fabricated with soft-lithography technique.At a temperature range from 19°C to 70°C,the fabricated LPWG filter element demonstrated a high temperature sensitivity of about 6.5 nm/°C and a wide linear tunable temperature range of 51°C,so that it can be used as a precise thermometer.Our results are useful for the designs of LPWG filters for the implementation of a wide range of thermo-optic functions.