Abstract: A programmable motion estimator having a memory and processing element array that implement a dual addressing scheme and a block rotating scheme that work together to perform block difference calculations required in video encoder subsystems to provide motion estimation with less processing power without comprising video quality.

Abstract: A technique for packet-switching suitable for interference-limited wireless communication systems is provided. Long bursty packets of data are broken into shorter units or packet-slots. This advantageously provides for averaging and minimizing interference in time--one of the requirements for achieving high system capacity in interference-limited systems. Transmit-start times and durations of packet slots are controlled by packet-slot distribution patterns. The patterns are representable by unipolar binary codes/sequences whose properties are based on number-theoretic principles. The technique minimizes the time variance of composite interference due to simultaneous transmissions of numerous signals over the same frequency channel. By minimizing the variance of overall interference, this technique satisfies the demand of multi-media traffic and also increases system capacity in a fading multipath environment.

Abstract: A rake receiver for use in direct-sequence code-division multiple-access communication systems employs a novel channel estimator capable of resolving multipath components spaced closer than a chip interval of the direct-sequence signature sequence. The estimator utilizes a constrained iterative deconvolution technique which employs projection onto convex sets (POCS). In a matched filter rake receiver embodiment, the delay T.sub.SC between two taps of a delay line is smaller than the duration T.sub.C of a chip of pseudo-random sequence. A rake receiver constructed in this manner is capable of detecting signals that have propagated through multipath channels and that have path components spaced closer than one chip of the signal sequence (i.e. closer than the inverse of the signal bandwidth).