Abstract: A filter and method for finite impulse response filtering an input signal is described. In one embodiment, the filter includes an input circuit configured to receive input samples in parallel, where the parallel input samples correspond to sequential samples of the input signal. In another embodiment, the filter includes a coefficient memory configured to store filter response coefficients and output a subset of those coefficients corresponding to a selected decimation factor.

Abstract: Transmitter-directed transmission security is provided between a transmit node and a receive node. The transmit node selects transmission format for each data frame based on a transmission security scenario. Information related to the transmission format is communicated between the transmit node and the receive node, and the data frames are transmitted over a wireless communication link using the selected transmission formats.

Abstract: Physical layer quality of service is provided for a wireless communication system by operationally adapting the physical layer format to the quality of service requirements of transmitted data. The physical layer formats for the data packets are selected based on the quality of service requirements of the data packets. Control information defining the formats is transmitted across the wireless communication link and the data packets are transmitted using the selected physical layer formats.

Abstract: A method and system is disclosed for demodulating multiple waveforms, with different modulation formats, in the same hardware by providing a software-configurable demodulator that configures itself in response to varying input waveform types. The system reconfigures its logic to accommodate the format of the signals being received and further allows for reconfiguration of demodulator functional block interfaces to remove downtime during multiple waveform processing.

Abstract: A block polyphase filter is constructed of a set of filter blocks having different filter functions, and being arranged for parallel processing of portions of an input sequence of signals. Signals of the input sequence are divided among the blocks by a demultiplexer for processing at a clock frequency lower than a clock frequency of the input signal sequence. The filter blocks are arranged in groups, wherein output signals of the blocks in any one group are summed to produce an output signal of the filtered group. Output signals of all of the filter groups are multiplexed to provide an output signal sequence wherein the repetition frequency of the signals may be higher, lower, or equal to the repetition frequency of the input signal sequence depending upon the ratio of the number of filter groups to the number of filter blocks in the set of filter blocks.

Abstract: A demodulator, suitable for use in a communication system and in a modem, has a block polyphase circuit with circuit blocks for different signal processing functions, particularly filtering, delay, and frequency conversion. The circuit blocks are arranged for parallel processing of different portions of an input sequence of signals. Signals of the input sequence to be filtered are divided among the blocks by a demultiplexer for processing at a clock frequency lower than a clock frequency of the input signal sequence. Signals outputted by groups of the circuit blocks are summed to produce an output signal of the group. Frequency and timing reference signals, as well as fractional delay interpolation, are produced also by parallel-channel circuitry. Output signals of all of the groups are multiplexed to provide an output signal sequence such that the repetition frequency of the outputted signals may be higher, lower, or equal to that of the input signal sequence.

Abstract: A modem, or a communication system, in its transmission section, has signal-formatting circuitry followed by circuitry for insertion of a sequence of pilot symbols into a sequence of data symbols outputted by the formatting circuitry. Placement of the insertion circuitry after the formatting circuitry permits a variety of formatting options without effecting the sequence of pilot symbols that serves as a time reference useful in detection of a signal transmitted by the modem. The reception section of the modem is equipped correspondingly to process a received composite signal of data symbols having a prescribed format and a sequence of pilot symbols. The reception section extracts the sequence of pilot symbols from the composite signal, and employs the pilot symbols to develop a time base for operation of circuitry for decoding the format of the received composite signal to extract data from the composite signal.