This contribution describes a modulation scheme suitable for satellite communication, which is based on FM and provides an increased bandwidth of 2 to 3 times that which is currently available commercially with QAM schemes. The system provides best advantage when used in high bandwidth links that occupy the whole transponder. This provides a potential throughput of over 400Mbits/s through a con...

-The constellation diagram is a representation of a signals modulated by a digital passband modulation scheme It displays the signal as a two-dimensional X-Y plane scatter diagram in the complex plane at symbol sampling instants. In a more abstract sense, it represents the possible symbols that may be selected by a given modulation scheme as points in the complex plane. Measured constellation d...

In this lecture we discuss construction of signals via a trellis. That is, signals are constructed by labeling the branches of an infinite trellis with signals from a small set. Because the trellis is of infinite length this is conceptually different than the signals created in the previous chapter. We the codes generated are linear (the sum of any two sequences is also a valid sequence) then t...

Many blind or semi-blind equalizers are implemented with the help of iterative algorithms, and therefore may require long convergene times or suffer from local minima. Closedform block blind equalizers are attractive, even if they are suboptimal, since they can serve to initialize them. But they can perform better in time-varying contexts, that is on very short data blocks. It is focused here m...

We propose a convolutional encoder over the finite ring of integers modulo pk ,Zpk , where p is a prime number and k is any positive integer, to generate a space-time convolutional code (STCC). Under this structure, we prove three properties related to the generator matrix of the convolutional code that can be used to simplify the code search procedure for STCCs over Zpk . Some STCCs of large d...

Security in sensor networks is more important than traditional networks as they are deployed in hostile environments and are more prone to capture. Trusted third party authentication schemes, public-key systems are not suitable owing to their high resource requirements. Key pre-distribution was introduced in [3] to solve this problem. Our scheme achieves identical connectivity compared to the r...

Bootstrapping secure communication among sensor nodes deployed in hostile environments is an important and challenging problem. A common approach to solve this problem is to use a key predistribution scheme in which each sensor node is assigned a subset of keys selected from some key pool. The resilience of a key pre-distribution scheme depends on the size of the key pool that the scheme uses f...

We introduce space–time block coding, a new paradigm for communication over Rayleigh fading channels using multiple transmit antennas. Data is encoded using a space–time block code and the encoded data is split into n streams which are simultaneously transmitted using n transmit antennas. The received signal at each receive antenna is a linear superposition of the n transmitted signals perturbe...

A new frame synchronization technique, which is robust to carrier frequency and phase errors, is proposed for -ary PSK systems. This technique is derived through modification of the procedure used for obtaining the maximum-likelihood (ML) rule in the paper by Gansman et al. The proposed rule is based on an operation called a double correlation which evaluates a correlation after properly multip...

We propose a key frame extraction mechanism to aid the Structure from Motion (SfM) problem when dealing with image sequences from video cameras. Due to high frame rates (15 frames per second or more) the baseline between frames can be very small and the number of frames can become unpractical to deal with effectively. The mechanism described in this paper is a preprocessing step designed to mak...