This paper discusses insights into the Vestigial Sideband (VSB) modulation format and advanced demodulation techniques that can be utilized to provide reliable 8-VSB terrestrial reception. VSB is a special form of amplitude modulation that maintains a small portion of the undesired (or redundant) sideband, often called a vestige. VSB has a long history and wide application in analog communicati...

A multiple hypothesismodulation QAM classification task is adressed in this paper. The classifier is designed within the rigorous framework of decision theory. A characteristic feature is extracted from the signal, and is compared to the possible theoretical features in the maximum likelihood sense. This feature is composed of a combination between fourth-order and squared second-ordercyclic te...

We present a technique to derive -quadrature amplitude modulation (QAM) signals from quaternary phase-shift keying (QPSK) constellations when = 2 and is an even number. By utilizing QPSK Golay sequences, we have constructed -QAM sequences with low peak-to-mean envelope power ratios. Several upper bounds for these -QAM sequences were derived.

We exploit pilot-aided (PA) transmission enabled by single-sideband (SSB) subcarrier modulation of both quadrature signals in the DSP domain to achieve fully feedforward carrier recovery (FFCR) in single-carrier (SC) coherent systems with arbitrary M-QAM constellations. A thorough mathematical description of the proposed PA-FFCR is presented, its linewidth tolerance is assessed by simulations a...

Introduction: Conventionally, the rectangular QAM (R-QAM) BER has been estimated by using various approximations or bounds. Most exact QAM BER results are obtained without taking into account the co-channel interference (CCI) [1, 2]. When CCI is considered, exact BER analyses procedures are performed only for BPSK [3–5] and QPSK [4, 5] systems. Hence, the contribution of this Letter is that we ...

In this paper, we present the true Cramér–Rao lower bounds (CRLBs) for the estimation of phase offset for common quadrature amplitude modulation (QAM), PSK, and PAM signals in AWGN channels. It is shown that the same analysis also applies to the QAM, PSK, and PAM CRLBs for frequency offset estimation. The ratio of the modulated to the unmodulated CRLBs is derived for all QAM, PSK, and PAM signa...

The effect of the companding process on QAM signals has been under investigation for the past several years. The compander, included in the PCM telephone network to improve voice performance, has an unusual affect on digital QAM data signals which are transmitted over the same channel. The quantization noise, generated by the companding process which is multiplicative (and asymmetric), degrades...

This article presents new rate-1 STBCs attending full diversity over every QAM constellation when the number of Tx antennas is a power of two. From the simulation results, our design performs very closely to the quasi-orthogonal code with constellation rotation over 4-QAM and 16-QAM in the case of four Tx antennas over quasi-static Rayleigh fading channels. Moreover, the proposed codes would no...

We investigate a carrier phase jitter synchronization technique for square M-ary quadrature amplitude modulation (M-QAM) coherent optical orthogonal frequency division multiplexing (CO-OFDM) signal employing a unique pilot’s system design, Feed forward maximum likelihood phase estimator as well as Wiener filter-type Minimum Mean square error (MMSE) interpolator. The wiener filter relies upon Ko...

In this paper, we propose a new modulation method combining code-division multiple access (CDMA) and quadrature amplitude modulation (QAM), called CDMAQAM. It transmits QAM symbols allocated based on a CDMA signal, and it has the benefit that QAM errors can be recovered if they are in a range where they can be absorbed by CDMA demodulation. We applied the method to railway signaling and develop...