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Recent years have shown how the performances of the standard radar systems can be significantly improved by using a multiple-input multiple output (MIMO) approach. MIMO technique is an already well studied method for communications applications thanks to the benefits that it offers in multipath fading environments. This paper is aimed to present the design of a new MIMO based, short range, surveillance...
We consider a beamforming based MIMO system equipped a large scale antenna array in the 60GHz band. In free-space, an optimal (primary) antenna subset is determined heuristically using stochastic approximation to take advantages of full antenna array with limited number of RF chains. As an extension, a smart obstacle avoidance strategy is integrated into the framework of antenna selection in case...
The power consumption of wireless access networks will become an important issue in the coming years. In this paper, the power consumption of base stations for mobile WiMAX, HSPA, and LTE is modelled. This power consumption is related to the coverage of the base station. The considered technologies are compared according to their energy efficiency for different bit rates at a bandwidth of 5 MHz. For...
This paper investigates multi-cell coordinated shared relay with joint processing (JP) scheme in interference limited network. In general, multi-cell coordinated shared relay network increases the Signal to Interference-plus-Noise Ratio (SINR) in cell edge users, but resource usage efficiency is decreased by two-phase transmission of relay protocol. We propose JP of cooperating BSs and shared relay...
In this paper, mobile WiMAX trials are analysed to investigate the vehicular down-link performance for a number of on-car antenna configurations. The directionality and optimum polarization of the vehicular antennas are shown to improve both the range and throughput of the system. These improvements are attributed to the additional directive gain, and the reduced multi-input multi-output spatial correlation...
We consider in this paper high spectral efficiency bit interleaved coded modulation (BICM) MIMO system where, after serial to parallel conversion and per antenna coding, spatial data streams are simultaneously transmitted by using an antenna array. We carry out the performance analysis of an earlier proposed detection algorithm for such system which is based on the combination of linear and non linear...
The MIMO system has been used widely in the modern telecommunication, but there is serious Inter-symbol Interference (ISI) in the process of communication. Blind equitation algorithm has been utilized to eliminate the ISI. This paper researched MIMO system based on constant modulus algorithm (CMA) and introduced variable step-size theories by analyzing the defects of the blind equitation algorithm...
The “Model Reference Adaptive Control (MRAC)” is a popular approach from the early nineties to our days. Its basic idea is the application of proper feedback that makes the behavior of the controlled system identical to that of the “reference model”. It has many particular variants with the common feature that they are designed by the use of Lyapunov's 2nd method. Though this approach normally guarantees...
MIMO system has been proven to provide higher capacity that is linear increase with the number of antennas. But this is true only in independent conditions, when the spatial-temporal fading correlation exists, the capacity may vary. In the study, the geometrical MIMO channel model is presented. Based on the formula of MIMO ergodic capacity, the capacity limits are investigated with arbitrary finite...
The performance of spatial multiplexing-based multiple-input multiple output (MIMO) systems using zero forcing (ZF) detector in frequency selective fading channels is analyzed in this paper. The approximation of a linear combination of Wishart matrices is used to derive the probability density function (p.d.f.) of output signal-to-noise ratio (SNR) expression. Analytical error rate expressions for...
Impact of the channel estimation error and feedback delay on the throughput of multi-input and multi-output (MIMO) downlink systems is investigated. The dynamic transmission schemes based on TDMA and SDMA with zero-forcing beamforming (ZFBF) are described and their associated system throughput are compared. It is shown that the system performance is sensitive to the channel estimation error, and degrades...
The sensitivity of MIMO error performance to imperfect receiver channel state information is examined. Measurements made at three different UHF frequencies are used to show the effect of parameters such as training and frame lengths on error performance. The results show that the amount of training directly influences the supportable symbol rate and that the level of degradation in performance due...
Recursive expectation-maximization (EM) algorithm along with stochastic approximation is employed in this paper to estimate unknown time-invariant/variant parameters. In addition, we modify the conventional Viterbi algorithm used in space-time encoder under the MIMO system, and give the recursive metric equation. The modified Viterbi algorithm can be used in the receiver when the MIMO channel information...
In contrast to the conventional QR-decomposition M (QRDM) algorithm, the unbiased MMSE metric based QRDM algorithm exploits MMSE metric instead of the maximum likelihood (ML) metric, leading to enhanced performance with less complexity. However, for an efficient hardware implementation, the sorting stages involved at every QRDM detection stage can still be quite time and resource consuming. Hence,...
We consider an optimal control problem of MIMO systems affected by external disturbances with known dynamic characteristics but unknown initial conditions based on stability degree constraint. The objective is to find an optimal control, by which the cost function minimum and the state with the optimal control having a higher mean-square convergence rate can be obtained. A feedforward and feedback...
Effect of antenna selection on channel capacity of MIMO system is studied in both full rank and rank deficient channel based on a modified Water Pouring algorithm. Simulation results show that in rank deficient channel transmit antenna selection will increase channel capacity while in full rank channel it will reduce the channel capacity. Meanwhile practical significance of antenna selection in full...
In this paper, we propose a maximum likelihood (ML)-like performance reduced computational complexity sorted orthotope sphere decoding (OSD), and zero forced (ZF) sorted OSD algorithms for the spatial multiplexing (SM) in a multiple-input multiple-output (MIMO) system. In comparison with the original OSD our technique reduces the number of partial Euclidean distance (PED) computations by up to 28%,...
Sphere decoding (SD) is an efficient algorithm which has been proposed in Multiple-input Multiple-output(MIMO) digital communications. Sphere decoding can avoids to search for the element like maximum-likelihood (ML) decoder thus reduces the decoding order of complexity effectively. However, SD also has high complexity in some situations. The complexity of the algorithm are controlled by radius and...
Spatial multiplexing MIMO wireless system is an excellent choice for next generation broadband multimedia communications because of its parallel transmission capability. A major challenge for such MIMO system is that it usually requires appropriate decomposition of both wireless channels and multimedia data bitstreams. Existing approaches to MIMO channel decomposition have been passively based on...
A compact broadband MIMO antenna array is developed in this paper. The omnidirectional radiation pattern of the antenna elements allows the array to receive a wide range of multipath signals, thus increases the SNR of MIMO systems. It is found by simulation and measurement that the array has an excellent performance under the MIMO propagation environment in a wide bandwidth (more than 40% at 2.1GHz)...
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