A quantummechanics based method is presented to generate sets of digital angles that may be well suited to describe projections on discrete grids. The resulting angle sets are an alternative to those derived using the Farey fractions from number theory. The Farey angles arise naturally through the definitions of the Mojette and Finite Radon Transforms. Often a subset of the Farey angles needs t...

In this paper, the performance of a cooperative Decode-and-Forward (DF) relay network with adaptive M-ary Quadrature Amplitude Modulation (M-QAM) is analyzed. A five mode adaptive M-QAM scheme is employed, and the system performance is investigated for both fixed switching levels and for optimized switching levels with a target bit error rate (BER) constraint. Expressions for average BER, spect...

We present a general algorithm for generating arbitrary standard complementary pairs of sequences (including binary, polyphase, M-PSK and QAM) of length 2 using Boolean functions. The algorithm follows our earlier paraunitary algorithm, but does not require matrix multiplications. The algorithm can be easily and efficiently implemented in hardware. As a special case, it reduces to the non-recur...

A closed form Bit Error Ratio (BER) formula is derived for a fixed-mode Quadrature Amplitude Modulation (QAM) scheme employing Rake receivers and receiver antenna diversity. The analysis is extended to constant power Adaptive QAM (AQAM) expressing the average BER and the average throughput as a closed form function of the modulation mode switching levels. Then, the switching levels are optimise...

In this paper a novel method to realize the synchronization process in case of 32-QAM will be presented. The system is based on the times-n carrier recovery and doesn’t depend on data decision. Starting from the Park and Ahn method which tracks, after a non linearity, the carrier recovery only for the in-phase symbols of a 16-QAM modulation, the proposed method combines a Phase Lock Loop and a ...

This paper proposes a carrier phase estimation of a power efficient APSK signal with a honeycombed constellation at a receiver in point-to-multi-point fixed wireless access systems using quasimillimeter frequency band. The signal has a lower amplitude level of a maximum signal vector than a conventional QAM signal. The signal also has a lower average output power. A reference carrier phase of t...

In this paper the BER performances are analyzed of a STBC encoded secured multiuser MIMO-OFDM wireless communication System. The 2X2 multi-antenna supported MIMOOFDM system implements RSA cryptographic algorithm and ZF and MMSE based linear pre channel equalization schemes with deployment of various digital modulations (16-QAM, 16PSK and 16-DPSK) over AWGN and Rayleigh fading channel. In this w...

This letter introduces two fast maximum-likelihood (ML) detection methods for 4*4 quasi-orthogonal space-time block code (QOSTBC). The first algorithm with a relatively simple design exploits structure of quadrature amplitude modulation (QAM) constellations to achieve its goal and the second algorithm, though somewhat more complex, can be applied to any arbitrary constellation. Both decoders ut...

| We derive generalized analytical constructions of linear realeld (LRF) codes for transmissions over wireless fading channels. We show cases where LRF-coded QAM, PAM, or PSK constellations can achieve maximum diversity and large coding gains. We construct analytically LRF codes, which not only yield larger coding gains than existing designs in most cases, but also produce LRF-coded QAM or PAM ...

Quadrature Amplitude Modulation (QAM) is used in both analog and digital communication. In this technique, both amplitude and phase varies of carrier wave with respect to digital data or information. It provides high data rate for transmission. QAM is used in many application like color television, Wi-Max, OFDM (Orthogonal Frequency Division Multiplexing), and in digital satellite communication...