A method and apparatus of communicating information using Time Division Multiple Access and adaptive transmission and reception are disclosed. Signal bursts are transmitted from TDMA transmitters to a TDMA receiver wherein the transmitter codes the information and transmits coded information to the receiver using at least one of two timeslots of a plurality of timeslots in a repetitive TDMA frame period. Both of the two timeslots are received whether or not the transmitter has transmitted using one or two timeslots and the received signals are classified as intended and non-intended. Successively received signals classified as intended are then assembled into a block for decoding to reproduce the information.

Dual mode satellite/cellular terminal

In this paper, the performance of fully digital synchronization techniques for time-division multiple-access (TDMA) differentially encoded 16-QAM signal transmission, over cellular mobile radio channels, is considered. The preamble-less feedforward nondecision-aided (FF-NDA) synchronization techniques used for symbol timing recovery, carrier phase recovery and amplitude gain control to overcome Rayleigh fading channel impairments, are described. Novel techniques for digital amplitude gain estimation are presented. The performance of the synchronization parameters' estimators at the receiver is evaluated by computer simulation over additive white Gaussian noise (AWGN) and slow Rayleigh fading environment. Statistical properties of the algorithms developed are evaluated in terms of the bias and variance of the estimated errors and are compared to the Cramer-Rao lower bound.

Preamble-less nondecision-aided (NDA) feedforward synchronization techniques for 16-QAM TDMA demodulators

A structure of a fully digital synchronisation unit for TDMA differentially encoded 16-QAM signal transmission, over cellular mobile radio channels, is considered. The feedforward non-decision-aided (NDA) synchronisation techniques used for symbol timing recovery and carrier recovery are described. A novel technique for carrier phase recovery is presented. The performance of the synchronisation parameters' estimators at the receiver are evaluated by computer simulation in a slow Rayleigh fading environment. The statistical properties of the algorithms developed are evaluated in terms of the bias and variance of the estimated errors and are compared to the Cramer-Rao lower bound.

http://ieeexplore.ieee.org/iel3/4477/12726/00587682.pdf

Feedforward synchronisation techniques for 16-QAM TDMA demodulators

/pdf/performance-analysis-of-mimo-ofdm-by-spatial-diversity-with-4tw6o8beyq.pdf

Performance Analysis of MIMO-OFDM by Spatial Diversity with STBC4

The multiple input multiple output (MIMO) antenna system provides very promising gain in capacity without increasing the use of spectrum, throughput, and power consumption. This is also less sensitive to fading, hence leading to a breakthrough in the data rate of wireless communication systems. In such systems, the antenna properties as well as the multipath channel characteristics play a key role in determining communication performance. This paper proposes the analysis and performance of Spatial Multiplexing technique of MIMO system.Here different fading channels like AWGN and Rician are used for analysis purpose. Moreover we analyzed the technique using high level modulations (i.e. M-PSK for different values of M). Detection algorithms used are Zero- Forcing and Minimum mean square estimator.

/pdf/ber-analysis-of-2x2-mimo-spatial-multiplexing-under-awgn-and-2kgv7xx4k9.pdf

Ber analysis of 2x2 mimo spatial multiplexing under awgn and rician channels for different modulations techniques

The modulation scheme in a mobile radio communication system must primarily satisfy the objective of achieving high spectral efficiency and narrow power spectrum. The emerging modulation technologies in the family of linear modulation and constant envelope techniques are described. Multilevel modulation, spectral efficiency, power spectrum and intersymbol interference are discussed. The effect of coding on transmission rate and improvement of SNR requirement is considered.

P.S. Mundra

Papers

The choice of a digital modulation scheme in a mobile radio system