Abstract: A matched filter has a circuit calculating an exclusive-OR of two input data, a circuit calculating an exclusive-OR of two codes corresponding to the two input data, respectively, and a correlation processor. The correlation processor, using the exclusive-OR of the two input data, one of the two input data, the exclusive-OR of the two codes, and the code corresponding to one of the two input data, calculates a correlation value of the two input data and the two codes.

Abstract: A method and apparatus for a spread spectrum matched filter with Doppler correction suitable for using in a radio frequency receiver. A principal idea of the invention is to reduce a waveform representing Doppler correction values into a simple Boolean combination that can simply represent the waveform and be built into the processing in the matched filter. Advantages are (1) faster use of the matched filter, resulting in faster signal acquisition, and (2) lower power consumption because clocking to load signal and/or Doppler correction values is reduced. In particular, received samples can be Doppler corrected for the nominal or mean Doppler shift plus local oscillator error as they are stored. The remaining Doppler shift is relatively small and can be removed by building a relatively few Doppler offsets into the processing logic for each matched filter tap. This saves time because the Doppler shift can be changed almost instantly.

Abstract: A method and system in which the numeric values to which counters in resampling control circuitry may be reduced. As a result, smaller registers to hold such reduced numeric values may be designed into hardware implementing said circuitry. These smaller registers present savings in processing power and hardware allocation, thereby potentially improving response times and cost efficiency of said hardware.

Abstract: A filter adaptor connects a computer to a network through a network connection. The network has a large plurality of broadcast type messages having a given protocol. Each of the broadcast messages has a destination field and a source field. The adaptor has a preference list of one or more fixed channels that the computer is capable of receiving. Each fixed channel has a channel identifier that is also listed in the preference list. Further, the filter adapter has a filtering process that monitors the source field and discards any message that does not have a source identifier in the source field that matches one of the channel identifiers on the preference list.

Abstract: An improved apparatus and method for performing sample rate conversion of digital sample values is disclosed. The sample rate conversion utilizes a finite impulse response filter that substantially eliminates the introduction of phase errors that plague conventional approaches. The computations required to implement the finite impulse response filter are provided in a hardware implementation that is efficiently constructed and utilized so as to be practical to implement in hardware as well as being fast enough to process the incoming samples in essentially real time. The digital sample values being processed by the invention can, for example, be audio, video or graphics related digital sample values. The sample rate conversion is suitable for scaling the size of the images (graphical or video) along one or more axes, or for time compression or expansion of an audio streaming rate.