Abstract: A spread-spectrum-matched-filter apparatus including a code generator, an in-phase-symbol-matched filter, a quadrature-phase-symbol-matched filter, an in-phase-frame-matched filter, a quadrature-phase-frame-matched filter, and a controller. The code generator generates replicas of a chip-sequence signal, which are used to set the symbol-impulse responses of the in-phase-symbol-matched filter and the quadrature-phase-symbol-matched filter. The in-phase-frame-matched filter and the quadrature-phase-frame-matched filter detect a despread-header-symbol-sequence signal and generate a maximum output signal which may be used as a data-start signal or for synchronizing the timing of the controller as to when to trigger sampling of the A/D converter, the output of the symbol-matched filters, detection of the data-symbol-sequence signal and other time-dependent processes.

Abstract: An improvement to a spread-spectrum code-division-multiple-access system, using a channel sounding signal from a base station (BS) to provide initial transmitter power levels for remote stations (RS). The base station has a BS-spread-spectrum transmitter for transmitting BS-spread-spectrum signals at a first frequency and a BS-spread-spectrum receiver for receiving RS-spread-spectrum signals at a second frequency. The RS-spread-spectrum signals are transmitted by the remote stations at the second frequency. The BS-spread-spectrum signals at the first frequency are outside the correlation bandwidth of the RS-spread-spectrum signals at the second frequency. The base station has a BS transmitter for transmitting a BS-channel-sounding signal at the same carrier frequency being used by the remote stations to transmit a spread-spectrum signal to the base station. The bandwidth of the BS-channel-sounding signal is much of the bandwidth of the BS-spread-spectrum signal.

Abstract: Encoding and transmitting packet-switched, spread-spectrum data. Data are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data are demultiplexed into sub-data-sequence signals. The sub-data-sequence signals are spread-spectrum processed and combined as a multichannel spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to make a packet-spread-spectrum signal. The packet-spread-spectrum signal is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The packet receiver depsreads the multichannel spread-spectrum signal, and multiplexes the despread multichannel spread-spectrum signal as received-encoded data. The received-encoded data is decoded by the intended recipient and may be stored in a receiver memory or outputted directly.

Abstract: An improvement for obtaining synchronization to a chip-sequence signal. The chip-sequence signal has a plurality of chips, and is embedded in a spread-spectrum signal. A shift register shifts or cycles a replica or delayed replica of the chip-sequence signal. The shift register has a plurality of taps, which correspond to the plurality of chips. A plurality of comparators compares the chip-sequence signal embedded in the spread-spectrum signal with the replica of the chip-sequence signal stored in the shift register. From the comparison, the plurality of comparators generates, for each tap of the shift register, a plurality of compared values at each comparator of the plurality of comparators. A plurality of counters up and down counts, from each comparator, a respective plurality of compared values. The respective plurality of compared values appears at an output of a respective comparator of the plurality of comparators. The plurality of counters thereby generates a plurality of totals, respectively.