Modulation plays an important role in transmission of single from transmitter to receiver in all communication systems. But it is vital in wireless communication and a lot of communication features including (data rate, error rate, symbol rate, bandwidth etc) depends upon it. In NS2 wireless network simulation BPSK is used for digital encoding and modulation of data [1,2]. The BPSK method is us...

In this paper, we describe the channel estimation based on time domain channel statistics. Using a general model for a slowly fading channel, we present the MMSE and LS estimators. The mean square error and symbol error rate for a BPSK system is presented by means of simulation results. Depending upon estimator complexity, up to 4 dB in SNR can be gained over the LS estimator.

The need for achieving higher data rates in underwater acoustic communications leverages the use of multi-input multi-output (MIMO) schemes. In this paper two key issues regarding the design of a MIMO communications system, namely, channel estimation and symbol detection, are addressed. To enhance channel estimation performance, a cyclic approach for designing training sequences and a channel e...

For evaluating the performance of wireless digital communication system the most important part is the simulation of wireless channel, as whole performance of the system is depends upon it. The Band limited communication channel, due to its dispersive time response, may restrict the high data rate, due to Inter symbol Interference (ISI). If the ISI is not taken care off and compensated may caus...

In this article, the symbol error probability (SEP) of OFDM systems using M-ary coherent demodulation communicating over time-varying sum of Nakagami-m fading channels is analyzed. The focus of this article is on the evaluation of OFDM signals in mobile radio applications, such as IEEE 802.11a, IEEE 802.16a, and digital video broadcasting (DVB) systems. The time variations of the channel during...

The present work addresses channel estimation based on the Minimum Mean Square Error (MMSE) and Least Square (LS) criteria and also considers time-domain channel statistics. It presents an optimal criterion for the pilots, and corresponding optimal designs enabling complexity reductions. Using a general model for a slowly fading channel, the MMSE and LS estimators and a method for modifications...

We present a new signaling concept which consists of transmitting an additional data rate to the original data rate that is determined by the channel bandwidth, the modulation scheme, and other physical-layer functions of the transmission system. This is accomplished by overlaying M excess symbols to each block of N primary symbols, with the excess symbol period being equal to N times the prima...

A new decoding algorithm that modifies error searching soft decision method is presented. The proposed algorithm improves the decoding error performance caused by repeated searching. It is shown that the simplicity inherent in the hard decision decoding is still maintained. This paper proposes an error correcting binary channel code which promotes symbol transition. This scheme exploits the err...

In this report we firstly propose a block-code based general model to combat the Inter-Symbol Interference (ISI) caused by frequency selective channels in a Multi-Input Multi-Output (MIMO) system and/or by asynchronous cooperative transmissions. The general model is not only exemplified by the TimeReversed Space-Time Block Code (TR-STBC) scheme, but also by the Asynchronous Cooperative Liner Di...