A VLSI design for a trace-back Viterbi decoder

A systolic Viterbi decoder for convolutional codes is developed which uses the trace-back method to reduce the amount of data needed to be stored in registers. It is shown that this new algorithm requires a smaller chip size and achieves a faster decoding time than other existing methods     

Channel Equalization Using Adaptive Lattice Algorithms

In this paper, a study of adaptive lattice algorithms as applied to channel equalization is presented. The orthogonalization properties of the lattice algorithms make them appear promising for equalizing channels which exhibit heavy amplitude distortion. Furthermore, unlike the majority of other orthogonalization algorithms, the number of operations per update for the adaptive lattice equalizers is linear with respect to the number of equalizer taps.     

Electromagnetic pulse propagation in a weakly nonlinear plasma

An investigation of the propagation of electromagnetic pulses in a weakly nonlinear, cold, collisionless plasma is described. It is found that a transverse electromagnetic pulse generates, through nonlinear effects, a small amplitude, longitudinal electric pulse field. The transient behavior of this longitudinal electric field is studied. One particular case is considered in detail: the nonlinear generation of a longitudinal electric field by a transverse electromagnetic pulse which is excited by a suddenly turned-on cosinusoidal electric field of frequencyomega_{0}. Computer plots of numerical calculations of the second-order transient longitudinal field are presented.     

Injection locking of an additive-pulse mode-locked fiber laser

Injection locking is utilized to synchronize an additive-pulse mode-locked fiber laser to an external pulsed 76.0-MHz laser source. The spectral and temporal performance of the additive-pulse mode-locked fiber laser and the required conditioning are discussed. A low-jitter temporal synchronization is achieved     

Application of Least Squares Lattice Algorithms to Adaptive Equalization

In many applications of adaptive data equalization, rapid initial convergence of the adaptive equalizer is of paramount importance. Apparently, the fastest known equalizer adaptation algorithm is based on a recursive least squares estimation algorithm. In this paper we show how the least squares lattice algorithms, recently introduced by Morf and Lee, can be adapted to the equalizer adjustment algorithm. The resulting algorithm, although computationally more complex than certain other equalizer algorithms (including the fast Kalman algorithm), has a number of desirable features which should prove useful in many applications.     

Imaging detector of temporally coherent radiation

We present an optical architecture and image processor capable of detecting and locating temporally coherent radiation that may be dominated by incoherent background radiation. The optical architecture makes use of a coherent light modulator that modulates light of sufficient coherence length while it leaves light of short coherence length unmodulated. The design of the coherent light modulator offers a substantially wider field of view than did past designs, permitting its application within an imaging system. The image processor synchronously detects the modulation imposed on coherent light while it rejects incoherent light fluctuations. Results of a laboratory test are presented. The system tested in the laboratory had a 26 degrees field of view and was able to detect and locate coherent radiation >30 dB below the background incoherent light level.