Large quadrature amplitude modulation (QAM) constellations are currently used in throughput efficient high-speed communication applications such as digital TV. For such large signal constellations, carrier-phase synchronization is a crucial problem because for efficiency reasons, the carrier acquisition must often be performed blindly, without the use of training or pilot sequences. The goal of...

Space-time codes employ constellations of complex matrices. There are many advantages if this constellation forms a group under multiplication. Special cases have been considered to date, but in this paper all such constellations are analyzed. For a given constellation, the Chernoff bound for the probability of error is an explicit rational function in the SNR. By comparing these functions, our...

An extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph  asks to find a subset  of the vertices of  of cardinality  such that the maximum weighted distances from  to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution.

The well-known uniform error property for signal constellations and codes is extended to encompass information bits. We introduce a class of binary labelings for signal constellations, called bit geometrically uniform (BGU) labelings, for which the uniform bit error property holds, i.e., the bit error probability does not depend on the transmitted signal. Strong connections between the symmetri...

In this letter , super-orthogonal space-time trellis codes (SOSTTC) are extended for quadrature amplitude modulation (QAM) constellations. A systematic set-partitioning method for QAM constellations is given. Furthermore, trellis shaping based on set partitioning is incorporated in SOSTTC with QAM symbols to achieve extra shaping gain. Peak constraints can be used to limit the constellation exp...

We propose a new differential modulation scheme for multiple-antenna systems based on square spacetime block codes (STBC) when neither the transmitter nor the receiver knows channel state information. Compared with the known differential unitary space-time modulation (DUSTM), the proposed constellations generally have multiple amplitudes and do not have group properties. This generalization pot...

We derive an analytical closed expression to compute the minimum distance (quantified by angle of separation measured from center Earth) between any two satellites located at same altitude and in circular orbits. also exploit several properties Flower Constellations (FCs) that, combined with our formula for distance, give efficient method angular satellites, all possible FCs up a given number s...