Error Performance Improvement Of A Multiplexed Mimo Systems Over Weibull Gamma Fading Channel Essay

In MIMO system there is multiple antennas is provided at the transmitter side as well as receiver side. Using multiple antennas at the transmitter and the receiver side could able to increase spectral efficiency, produces higher capacity and provides more data rates for wireless communication. In MIMO system there is SU-MIMO that is called single user MIMO in which when there is data rates need to be increased for single user then it is known as SU-MIMO, and if there is individual stream is allocated to multiple users; then it is called multiuser MIMO (MU-MIMO).

I do agree with you. MiMo district is a nice place to visit and spend time with friends. MiMo's top management has to assign to the public relation department create an marketing plan to educate the residents of Miami in reference to the high crime in MiMo district has dropped compared with previous year. MiMo Public Relation must work closely with the community to promote MiMo brand name and

Transmitting data with elevated peak rate and small activity cycle in the downlink rapidly causes the channelisation codes under a solitary scrambling code to start to come to an end. In order to circumvent this complication, fundamentally two alternatives exist: exercise of either supplementary scrambling codes. The supplementary scrambling code approach loses the benefit of the transmissions being orthogonal from a single source, and consequently should be avoided. Using a shared channel resource maintains this benefit and in the mean time lessens the downlink code resource

The paper I read is “Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas” written by Thomas L. Marzetta. This paper was published in IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 9, NO.11, NOVEMBER 2010. The pilot signal is a direct sequence spread spectrum signal continuously sending by the base station. It makes the base station could send data in the forward-link and demodulate cell phone signals in the reverse-link. The pilot signal is known as confessed, like 000000 or 111111. In frequency re-use technology, we divide the space into several cells. Due to the same or correlated pilot sequence re-use in contiguous cells, the base station will inadvertently send data to terminals in other cells or collect and combine reverse-link signals from terminals in other cells when processing. This is called pilot contamination. In this paper, the author mainly talk about the environment of multi-user(MIMO) operation with an infinite number antennas in the base station. He thinks that in this

Wheat, Hiser, Tucker, Neely and McCullough (2011) define fixed wireless networks as a technology which utilizes line-of-sight technology with both the transmitter and receiver at fixed locations (p. 159). The Fresnel zone within which the signals operate must be clear of any form of obstruction in order to avoid absorption and loss of signal strength. Wheat et al. , gives examples of fixed wireless technologies as Wireless Local Loop technologies, Multichannel Multipoint Distribution Service (MMDS), Local Multipoint Distribution Service (LMDS) and Point-to-Point Microwave.

Multiple-input multiple-output (MIMO) [2, 3, 30, 31] systems were introduced in order to enhance the performance of the wireless communications systems to provide robustness, high data rates, and reliability by overcoming the channel fading with the use of multiple antennas. A MIMO system offers redundancy through the multiple independent channels, which are created between the transmitting and the receiving antennas of the system. Using multiple-input multiple output systems, significant improvements are made in the coverage ranges of the communication systems and the data throughput without the need for additional transmission power or bandwidth expansion.

Abstract- In this paper, ordered successive interference cancellation (OSIC) is adopted with minimum mean square error (MMSE) detection to enhance the multiple-input multiple-output (MIMO) system performance. The optimum detection technique increases the system complexity with improved error rate performance. Therefore, MMSE-OSIC detection is used which gives reduced error rate compared to traditional MMSE with a considerable level of complexity. The system performance is analyzed in a composite fading environment which deals with multipath and shadowing, known as Weibull-gamma (WG) fading environment. Along with the composite fading, a composite noise i.e. additive white generalized Gaussian noise (AWGGN) model is taken into account to form various noise scenarios such as impulsive, Gamma, Laplacian, Gaussian and uniform noise. Consequently, generalized Q- function is used to develop such noise scenario. The average symbol error probability (ASEP) of MIMO system is computed for 16-quadrature amplitude modulation (16-QAM) using MMSE-OSIC detection in WG fading with AWGGN. Analytical expressions are evaluated in terms of Fox-H function (FHF). These expressions demonstrate the best fit to simulation results.

The paper presents the design of channel estimation and blocking probability for multi-hop wireless communication network (MH-WCN). This work proposed a bidirectional network coding 4−hop transmission strategy and followed by 2N−hop WCNs. The proposed method follows two steps. Firstly, assign composite channel coefficients at desired nodes and then derived the MSE performance expression for the proposed LMMSE estimation scheme, and an optimal training scheme has been designed to minimize MSE. Secondly, Fault-tolerant wavelength assignment algorithm. This method checks for the establishment of fault-free path, when path established, assign a particular wavelength to the established path. The experimental results shows the LMMSE, blocking probability and ML estimators have demonstrated effectiveness to improve the estimation accuracy in 4−hop WCNs.

Abstract multiple carriers are simultaneously modulated using Orthogonal frequency-division multiplexing (OFDM) which is a transmission technique. Since the OFDM-based system has high spectral efficiency and is robust against intersymbol interference and frequency-selective fading channels. The major problem of this system is high peak-to-average power ratio (PAPR) of transmitted signal which causes distortion of signal.

Cooperative communication is a new concept of research and it is a powerful technique to mitigate fading in wireless relaying layout. Concerning with the fading problem, this paper is focuses to give a better non-orthogonal space-time block code (STBC) scheme and assimilate it in the cooperative relaying nodes for upgrading performance of the system. Golden coded has also been incorporated in IEEE 802.16 (Wi-MAX) standard as a full rate full diversity space-time code and proven to present a ranking performance in a wireless MIMO (Multiple Input Multiple Output) scenario than any other code. At the receiver, maximum likelihood detection of different symbol is achieved through decoupling of the signal transmit from different antenna rather than joint detection. In this paper multihop wireless relay consisting of source, relay and destination each equipped with two antennas have been taken into account using decode-and-forward cooperative protocol strategy in relay nodes. The simulation results support the effectiveness of the proposed scheme by offering better SER performance and increased spectral efficiency than other codes.

Abstract— In this paper, performance metric of orthogonal frequency division multiplexing (OFDM) system is analyzed over a composite fading channel i.e. generalized K- fading channel. Here, OFDM system is considered which include repetition code to enhance the wireless link performance with simplicity. Symbol error rate (SER) performance is evaluated using binary phase shift keying (BPSK) and 16-qardature amplitude modulation (16-QAM) over generalized-K fading channel. This channel model considers Nakagami-m distribution to define multipath and gamma distribution to represent shadowing. Simulation results demonstrate that improved system performance can be achieved using repetition code in severely faded environment. A comparative study of coded and uncoded system is also given in this paper. Consequently, SER performance is improved with the increase in shape parameters.

nodes in the measurement model. Signals between the transmitter and receiver are always contaminated with noises. In the most cases, it is assumed that the measurement noise is an additive and Gaussian noise. This assumption is not always true. Measurement signals corrupted by multiplicative noise are presented in some systems such as discrete-time linear systems [3], control systems [4], communication systems [5] and tracking systems [6]. A crucial point is that the measurement error increases as a function of distance

Orthogonal Frequency Division Multiplexing is considered as an advanced communication model which has wide range of applications such as 3G, 4G, and Wi-Fi etc. Though orthogonal frequency division multiplexing has lots of advantages over conventional communication models such as FDMA, CDMA still it has some disadvantages in that the major drawback is Peak to Average Power Ratio. In literature several theories are proposed to resolve this issue but none of the algorithm is designed to meet the practical approach. In our work a novel approach is present to resolve the Peak to Average Ratio by introducing the variable slopes parameters K1, K2 and inflexion points A (A>0) and CA (0<C<1) in the probability density function in the Non Linear Companding Transform Technique then based on the inflexion point and variables parameter analysis, the

[1]S. M. Alamouti, describes a simple two-branch transmit diversity scheme. Using two transmit antenna and one receive antenna, the new transmit antenna provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit and two receive antennas. The scheme easily be generated to two transmit antenna and M receive antenna to provide a diversity order of 2M. This scheme does not require any bandwidth expansion any feedback from the receiver to the transmitter and its computation complexity is similar to MRRC. This also provide diversity improvement to all the remote units in a wireless system, using two transmit antennas at the base station instead of two receive antenna at all the remote terminals.

The data rate of Li-Fi system is based on switching timing of LED component. Switching speed of an LED can be much faster than a Wi-Fi frequency, with a much larger potential to carry data. Additionally, a polarization can be used for even faster in MIMO type system, as polarizing light is much easier than a radio wave. Thus, in a MIMO system that has multiple transmitters e.g. LEDs and receivers e.g. photodetectors (PD) are used to improve the data rates, significantly security as well as easing of deployment.