A Paradigm For Multiple Input Multiple Output ( Mimo ) Channel Modeling Demands Diversity Technique Essay

In the Multihop Virtual Multiple Input Multiple Output (MIMO) the data are collected by multiple source nodes and transmitted to a remote sink by multiple hops [11]. In this, the cluster head sends message to sensor nodes in the cluster. Next the sensor nodes encode the data and sends to cluster head in the next hope according to the orthogonal Space Time Block Code [STBC]. It saves the energy and provides QoS provisioning.

The version of MIMO using single input multiple output has the advantage of being easy to implement, but the disadvantage is that the receiver requires processing. This causes battery drain.

The block diagram of decoding process for a t-error correcting BCH code is illustrate in figure 1. For further information on BCH codes, we orientate readers towards references [21, 22].

The market for wireless communications has experienced incredible growth over recent years and wireless LANs have rapidly become a very

MIMO antenna configuration is requires in spatial multiplexing. In spatial multiplexing the high rate signal is divide into low rate signals and each individual stream is transmitted from different transmit antenna which is having the same frequency channel. Spatial multiplexing is technique which is capable of increasing channel capacity at higher signal to noise

R G Gallager [1] in his paper, the overview of low density parity check codes are presented. The parity check matrix specifies these codes, which consists of few entries of non-zero elements. The number of non-zero elements in row should be greater than the number of non-zero elements in column. The typical minimum distance of these codes are directly proportional to block length for a fixed rate. A simple but non optimum decoding scheme operating directly from the channel is described. As block length increases, complexity of equipment and data

Communication systems consist of transmitter, channel, and receiver. The latter can be affected by a noise source, such as the Additive White Gaussian noise (AWGN) which, in turn, can cause a change in the data transmission. As a result of data change or corruption, the idea of channel coding was introduced as a reliable solution to overcome this dilemma. Nowadays, we use some techniques as Forward error correction (FEC) to reduce the errors that might appear during the information transmission over the channel. In this technique, the system adds redundant (extra) bits to identify if a specific bit is corrupted or not and correct it. FEC Channel codes may be classified into two main categories: the Convolutional Code and the Block Code. On

It’s very important to determine the device and application requirements based on bandwidth, protocols and frequency. In wireless network, bandwidth, protocols and sometime environmental conditions affect the speed of the channel so we need to calculate the aggregate throughputs before designing the network. Today, users carry Wi-Fi devices such as notebooks, laptops, tablets and Smartphone’s so total throughput must be calculated by estimating number of connections rather than the number of the seats. Some common wireless networking standards such as 802.11a/b/g/n invented in the IEEE association must be supported by wireless network. For better performance and for faster devices (802.11n devices), dual-ratio access points should be deployed. Table1 [3] illustrate the different IEEE standards and throughput.

Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking

The wireless channel is different and much more unpredictable than the wire line channel because of factors such as multipath and shadow fading, Doppler shift, and time dispersion or delay spread. These factors are all related to variability introduced by mobility of the user and the wide range of environmental conditions that are encountered as a result.

ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING techniques allow the transmission of high data rates over broadband radio channels subject to multipath fading without the need for powerful channel equalization. However it is very sensitive to nonlinear effects due to the high PEAK TO AVERAGE POWER RATIO owned by their transmitted signals. Slimane Ben Slimane (2007) proposed an efficient technique for reducing the PEAK TO AVERAGE POWER RATIO of ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING signals. The proposed technique is data-independent that does not require new processing and optimization for each transmitted ORTHOGONAL FREQUANCY DIVISION MULTIPLEXING block. The reduction in PEAK TO AVERAGE POWER RATIO of the ORTHOGONAL FREQUANCY DIVISION

OFDM provides the frequency selective channel which can able to divides the frequency band into multiple sub channels and each sub channel carries a different stream of symbols. There is flat frequency response throughput each sub channel when there is narrow bandwidth of each sub channel. Therefore OFDM able to transform a frequency selective channel into set of multiple flat-fading channels. Simultaneously when M transmit antennas used an OFDM transmitter, and N receive antenna used OFDM front end then L flat fading MIMO channel is formed from MIMO frequency selective channel with having dimensions equals to MxN. Earlier traditional space time codes were not optimal for takeout the additional

The hοme autοmatiοn is cοntrοl οf hοme devices frοm a central cοntrοl pοint, autοmatiοn is tοday’s fact, where mοre things are being cοmpleted every day autοmatically, usually the basic tasks οf turning οn οr οff certain devices and beyοnd, either remοtely οr in clοse prοximity The cοncept οf the RF-based systems is tο use the underlying wireless data netwοrk such as IEEE 802.11 (Wi-Fi). The pοpularity οf wireless netwοrks in hοme has increased in recent years, and the advanced cοmputer technοlοgy has made the persοnal digital device tο cοmmοnly have the capability tο cοmmunicate thrοugh the wireless netwοrk. Hence, it is suitable tο use RF-based lοcatiοn determinatiοn system tο estimate the lοcatiοn οf the persοnal digital device in a hοme envirοnment, with high data rate transmissiοn, suppοrting multimedia applicatiοns may be feasible in WLAN . Οne οf the pοssible applicatiοns are wireless netwοrks fοr hοme autοmatiοn. Imagine a private hοme equipped with mοtiοn, light, temperature and οther sensοrs and actuatοrs fοr οpening the dοοr, dimming the light, cοntrοlling the heating and sο οn . It can be as basic as dimming lights with a remοte cοntrοl οr as cοmplex as setting up a netwοrk οf items in yοur hοme (such as a thermοstat, security system, lighting and appliances) that can be prοgrammed using a main cοntrοller . The basic idea οf hοme autοmatiοn is tο emplοy sensοrs and cοntrοl systems tο mοnitοr a dwelling, and accοrdingly adjust the variοus mechanisms that prοvide

In designing base stations, it is very important to have the knowledge about the electromagnetic environment where the system is operated, and the location of the transmitter and receiver. it is difficult to predict indoor radio propagation because of the dense multipath

Code division multiple access (CDMA) is a technology which is used for radio communication purpose. Multiple access technique is a broad area for communication purpose , CDMA is an example of multiple access technology, through which several number of transmitter can send information in a single communication channel. In case of CDMA a particular bandwidth can shared between several number of users. To permit this technique to achieve without undue interference between users, spread spectrum technology and a special coding scheme are used by CDMA.