Time-division multiplexing

Multicarrier modulation is a technique of transmitting data over several subchannels instead of transmitting the data over the whole bandwidth in single carrier systems. The data stream to be transmitted is divided into a number of lower data rate data streams. The subchannels have narrow bandwidth compared to wideband channel in single carrier systems and also the symbol period on each subchannel is increased. Multicarrier modulation provides immunity to fading caused by data transmission over

of the wireless communication are the multipath reception. We can receive signal not only through Line of Sight but also reception can be made through a large number of reflected radio waves that arrive at the receiver at different times. The difference in arrival time is caused due to trees, vehicles, buildings, rocks etc. FIGURE1: MULTIPATH PROPAGATION [5] These reflected waves interfere with the direct coming received wave and the other

OFDM is a great technique to handle impairments of wireless communication channels such as multipath propagation. Hence, OFDM is a practical candidate for future 4G wireless communications techniques [1]-[4]. On the other hand, one of the major drawbacks of the OFDM communication system is the drift in reference carrier. The offset present in received carrier will lose orthogonality among the carriers. Hence, the CFO causes a reduction of desired signal amplitude in the output decision variable and

AWGGN. Analytical expressions are evaluated in terms of Fox-H function (FHF). These expressions demonstrate the best fit to simulation results. Keywords- MIMO, MMSE-OSIC, WG fading, AWGGN, M-QAM, ASEP. 1. Introduction In MIMO systems, spatial multiplexing is used for high data rate transmission and spatial diversity is used to achieve reliable communication. However, there is a tradeoff between diversity and

Error Performance improvement in Spatially Multiplexed MIMO Systems over Weibull-Gamma Fading Channel Keerti Tiwari and Davinder S. Saini Department of Electronics and Communication Engineering Jaypee University of Information Technology Waknaghat, Solan, (H.P.) - 173234, India E-mail- keerti.tiwari@mail.juit.ac.in, davinder.saini@juit.ac.in Abstract- In multiple-input multiple-output (MIMO) systems, spatial demultiplexing at the receiver is a motivational task. Thus, several detection techniques

5.1 OFDM-IDMA Scheme Various multiple access technique like TDMA, CDMA, FDMA has been used in wireless network for communication. But OFDM i.e orthogonal frequency division multiple access offers number of advantages over these multiple access techniques, such as this scheme can provide simple treatment against ISI and also reduces cross cell interference. The IDMA in combination with OFDM allow effective and simple turbo type iterative MUD algorithm which can be easily implemented to large number

least keep the interference, if any, to a minimum degree so that users can reliably communicate with their intended destinations. The full name of the mentioned multiple scheme are as follows: FDMA – Frequency division multiple access WDMA – Wavelength division multiple access CDMA – Code division multiple access In deterministic protocol, users know exactly when transmission is allowed in the shared channel as some sort of a regulation or rule

Mobile telephone call: A mobile device initiates a call by sending the number of the called device on the preselected setup channel. In this process, the the mobile device firstly checks whether the setup channel is idle by examining information that comes from the BS channel. If it finds that the setup channel is idle, the mobile device may transmit the information of number to the BS. The BS then sends the request to the MTSO. Mobile device paging: The MTSO then tries to complete the connection

channel in wireless communication systems, also regarded as air-interface as mentioned previously. Thus, also making effective use of allocated bandwidth. The following three techniques come under this category: FDMA – Frequency División Multiple Access TDMA – Time Division Multiple Access CDMA – Coded Detection Multiple Access For, FDMA, an allocated bandwidth over the channel is divided among the users connected over that channel. In, TDMA, each of the users take turns to transmito r reciveve data

INTRODUCTION: 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