Abstract: A communication system receives a modulated signal that carries encoded communication data. An adaptive filter has a plurality of adaptive filter taps and weighted coefficients and a variable delay circuit operative before the adaptive filter taps for separating the spacing of multipath introduced by adaptive filter and producing a filtered output signal with improved multipath performance. A demodulator and decoder receive the filtered output signal from the adaptive filter and demodulate and decode the signal to obtain the communications data.

Abstract: A communications system receives a modulated signal that carries encoded communications data. An adaptive filter has an input, a plurality of non-adaptive and adaptive filter taps with weighted coefficients, and an output. The received signal is passed through the adaptive filter and around adaptive filter and a switch selects which signal to pass to demodulator based on measured output power of the adaptive filter and of the original received signal. A demodulator and decoder receive the filtered output signal and demodulate and decode the signal to obtain the communications data.

Abstract: In accordance with the present invention, the system and method removes interfering signals from a communications signal and includes a Fast Fourier Transform (FFT) circuit for taking the FFT of a received signal and segmenting the signal into segments. A frequency shifting circuit can shift each segment in frequency to place an interfering signal within a single FFT band to be later substantially nulled. An inverse FFT circuit can place the segments of signals back within the time domain.

Abstract: A system communicates data and includes an encoder for encoding communications data with a forward error correction code. A data randomizer randomizes the communications data with a random bit sequence and a combining circuit combines the communications data with known symbols into frames. A modulator maps the communications data into minimum shift keying or Gaussian minimum shift keying (MSK or GMSK) symbols based on a specific mapping algorithm to form a communications signal having an MSK or GMSK waveform over which the communications data can be transmitted.

Abstract: A system apparatus and method generates a communications signal having an error detection mechanism. A circuit generates a data packet. An encoder multiplies and accumulates data words with values in a distance table containing non-repeated n-bit multipliers having “m” number of one bits that are set to obtain accumulated sum bits and appends the accumulated sum bits to the data packet as an error detection code to form a communications signal to be transmitted.

Abstract: Method for modulating an RF signal includes the steps of modulating an RF signal using frequency shift keying (FSK) modulation to define a plurality of symbols (2030, 2031). The FSK modulation includes transitioning the modulated signal (204) between at least two different frequencies (f1 and f0) during a guard period (210). The method includes the further step of varying a frequency of the modulated signal 204 during the guard period (210) in accordance with a predetermined rate of change. The predetermined rate of change is selected to minimize a bandwidth of the RF signal.

Abstract: A communication system includes a plurality of nodes forming a wireless mesh network. A plurality of wireless communication links connect the nodes together. Each node is formed as a communications device having a physical layer and a media access control (MAC) layer in accordance with the Open System Interconnect (OSI) model and operative for transmitting and receiving communications packets to and from other nodes via the wireless communication links in an Automatic Repeat Request (ARQ) mode. The physical layer monitors channel parameters of the wireless communications link when in an ARQ mode and, based on the channel parameters, communicates to the MAC layer over-the-air (OTA) parameters used for transmitting packets.

Abstract: A programmable decoder includes at least one programming input for a plurality of programmable, reduced state trellis parameters. A programmable device is connected to the at least one programming input and implements a Reduced-State Sequence Estimation (RSSE) decoder comprising at least one reduced-state trellis structure based upon the plurality of programmable reduced-state trellis parameters, including one of at least the number of super-states, the number of full-states, the number of branches per super-state, a reverse super-state trellis table, a decoder super-state survivor as a full-state, a forward full-state table, a full-state to super-state mapping table, a decoder super-state path metric and decoder super-state traceback array.

Abstract: A decoder includes at least one programming input for a plurality of programmable reduced-state trellis parameters. A programmable device is connected to the at least one programming input and implements a reduced-state maximum likelihood decoder that is operable for processing a continuous phase modulated (CPM) signal and returning up to N bits that were transmitted based on a maximum likelihood and current winning super-state and corresponding survivor full-state. The programmable device calculates the path metrics for every super-state and determines a best path based on the reduced-state trellis parameters.

Abstract: A communications system of the present invention includes a transmitter that is operative for combining an orthogonal Walsh modulation with a minimum shift keying or Gaussian minimum shift keying waveform to form a hybrid communications signal that carries communications data over a constant amplitude waveform that is spread in time and frequency. This communications signal can be transmitted to a RAKE receiver that has a plurality of correlators with output weights formed for processing this hybrid communications signal.

Abstract: A communications system includes a transmitter having an encoder for encoding communications data and varying at least one of a puncturing of the code rate and a repetition rate on different portions of the communications data. As a result, a variable forward error correction is added to different portions of the communications data.

Abstract: An adaptive link assignment scheme for dynamically changing communication node topologies such as satellite networks, fleets of ships or aircraft, etc. Periodically each node in the network transmits topology information to all the nodes in the network. Then each node determines the degree of connectivity of the network. It is preferred that the network be at least triconnected, and if the network is less than that each node determines what connections it can make to improve the network connectivity. If more than one alternative is available, a choice is made based on line of sight endurance and then on traffic delay. The identification of the selected connection is then broadcast to all the nodes in the network. Each node thus receives the proposed changes from all the network nodes, and each node then resolves conflicts between the broadcast selections and determines what change it should make. Finally, the changes are implemented.