Performance Evaluation of channel capacity in WLAN medium of MIMO systems (original) (raw)
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Performance Evaluation of Channel Capacity In MIMO System
2011
The demand for Multiple-input Multiple-output (MIMO) system is growing at an explosive rate with the anticipation that communication to a end user anywhere on the globe at all times will be available in the near future. Water-Filling Algorithm (WFA) is presented for MIMO Rayleigh fading environment under Channel Side Information (CSI) is known and unknown at the transmitter. We mainly demonstrate on efficient use of information theoretic Capacity of independently and identically distributed (i.i.d.) MIMO Rayleigh flat fading channels. However, the capacity gain is reduced if the CSI is not perfect. Assuming each antenna in Transmitter is allocated equal amount of power which maximizes capacity. To achieve high capacity gain the reported algorithm can effectively be optimized for maximizing the channel capacity. We also compared the ergodic channel capacity and channel outage capacity with simulation results. We show that the proposed scheme is spectral efficient, as it offers the fu...
CHANNEL CAPACITY ESTIMATION IN MIMO-OFDM SYSTEM OVER RAYLEIGH FADING CHANNELS
In wireless communications, there is an endless quest for high channel capacity and improved quality.MIMO could increase the capacity of wireless communication system considerably compared to SISO.Fading causes poor performance in a communication because it can result in a signal power loss without reducing the noise power.OFDM could obtain good performances in multi-path frequency-selective fading channels.The closed form expressions of ergodic capacity of MIMO-OFDM systems is derived when transmitter has no channel state information(CSI) and the receiver has perfect CSI.In this paper, channel capacity of MIMO-OFDM system is estimated using Rayleigh fading channels under different system specifications like number of transmit and receive antennas and different power levels.
The presented research paper aims to analyze the channel capacity of a MIMO System in Rayleigh fading channel with different antenna nodes and spacing. It is argued that an implementable model is not readily available in the evaluated reference papers. As such a model is developed for simulating spatially correlated MIMO system in Rayleigh fading channel. To verify the developed model, a MATLAB code is devised to simulate the capacity of MIMO system for different numbers of antenna nodes and that is depicted in the comparative result MIMO systems have collected extensive attention in the new millennium due to its promise for a considerable increase in capacity, which is commonly considered to be a viable means for satisfying the ever-increasing demand for a higher data rate. The ground-breaking work by Telatar [1], Foschini and Gans [2] toward the end of last millennium not only provided some exciting results on capacity of multiple-antenna Gaussian channels but also stimulated a huge wave of enthusiasm toward various topics involving MIMO systems, including MIMO channel capacity, MIMO channel coding, space-time coding, etc. Among all lot of research and analysis is done in the area of channel capacity by modeling various channels and developing various algorithm.
Capacity and power allocation for fading MIMO channels with channel estimation error
IEEE Transactions on Information Theory, 2000
In this correspondence, we investigate the effect of channel estimation error on the capacity of multiple-input-multiple-output (MIMO) fading channels. We study lower and upper bounds of mutual information under channel estimation error, and show that the two bounds are tight for Gaussian inputs. Assuming Gaussian inputs we also derive tight lower bounds of ergodic and outage capacities and optimal transmitter power allocation strategies that achieve the bounds under perfect feedback. For the ergodic capacity, the optimal strategy is a modified waterfilling over the spatial (antenna) and temporal (fading) domains. This strategy is close to optimum under small feedback delays, but when the delay is large, equal powers should be allocated across spatial dimensions. For the outage capacity, the optimal scheme is a spatial waterfilling and temporal truncated channel inversion. Numerical results show that some capacity gain is obtained by spatial power allocation. Temporal power adaptation, on the other hand, gives negligible gain in terms of ergodic capacity, but greatly enhances outage performance.
Practicable MIMO Capacity in Ideal Channels
2006 IEEE 63rd Vehicular Technology Conference
The impact of communications signal processing such as QAM modulations (instead of gaussian signals), finite block lengths (instead of infinitely long codes), and using simpler algorithms (instead of expensive-to-implement ones), etc., is a lower practicable capacity efficiency than that of the Shannon limit. In this paper, the theoretical and practicable capacity efficiencies for known-channel MIMO are compared for two idealized channels. The motivation is to identify worthwhile trade-offs between capacity reduction and complexity reduction. The channels are the usual complex gaussian random i.i.d., and also the complex gaussian circulant. The comparison reveals new and interesting capacity behaviour, with the circulant channel having a higher capacity efficiency than that of the random i.i.d. channel, for practical SNR values. A circulant channel would also suggest implementation advantages owing to its fixed eigenvectors. Because of the implementation complexity of water filling, the simpler but sub-optimum solution of equal power allocation is investigated and shown to be worthwhile.
Capacity Analysis of Multiple-input-multiple-output System Over Rayleigh and Rician Fading Channel
Yazen Saifuldeen Mahmood, 2019
This paper aims to analyze the channel capacity in terms of spectral efficiency of a multiple-input-multiple-output (MIMO) system when channel state information (CSI) is known using water-filling algorithm and unknown at the transmitter side which it has been shown that the knowledge of the CSI at the transmitter enhancing the performance, the random Rayleigh and Rician channel models are assumed. Ergodic capacity and outage probability are the most channel capacity definitions which are investigated in this study. MATLAB code is devised to simulate the capacity of MIMO system for different numbers of antenna nodes versus different signal-to-noise ratio (SNR) values. In addition, the outage capacity probabilities for vary transmission rate and SNR are discussed.
Capacity Analysis and Power Allocation over Non-Identical MISO Rayleigh Fading Channels
2008 IEEE International Conference on Communications, 2008
We analyze the capacity of a multiple-input singleoutput system over Rayleigh fading channels. The channels are assumed to be independent and non-identically distributed. Simple, explicit and closed-form expressions of ergodic mutual information and outage probability are obtained. Moreover, two suboptimal but efficient analytical power allocation schemes for mutual information maximization and outage minimization are derived, respectively. In specific, for mutual information maximization, more power is assigned to those channels with higher channel variances, while for outage minimization the power allocation scheme follows the water-filling principle.
Channel Capacity Optimization Using Multiple-Input Multiple-Output for a Rayleigh Channel
European journal of electrical engineering and computer science, 2023
The use of multiple-input multiple-output (MIMO) systems with multiple antenna elements provides an efficient solution for future wireless communication. In recent times, wireless communication has been characterized by high speed, higher data throughput, and high Bit Error Rate (BER) in a limited bandwidth. Low data speed handover, low Signal Noise Ratio (SNR), and hardware power drainage are common channel problems with wireless systems. The objective of this research seeks a way to optimize channel capacity and enhance system performance. The paper presents a comprehensive performance analysis of channel capacity under the Rayleigh fading channel using water water-filling technique. MATLAB was used to analyze and simulate the process. Simulation results revealed that the water-filling algorithm can effectively optimize channel capacity in the wireless communication system.
On the Power Allocation of MIMO Channels
pupr.edu
In this paper we consider MIMO system with M t transmitting and M r receiving antennas, when channel state information (CSI) is known on the transmitter side. The Reyleigh fading channel propagation condition is assumed. In this case, the optimum transmission consists of allocating the transmitted power for each virtual sub-channel related to the corresponding eigenvalue of the channel matrix. The optimum power allocation is computed using the water pouring algorithm (WPA). However, a real-time implementation of the algorithm requires serious computational work, which is O(M 2 t). We propose a modification to WPA that reduces the computational complexity to O(M t).