Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) with a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations. Each remote station (RS) has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The improvement includes the steps of transmitting from the BS-spread-spectrum transmitter, a broadcast common-synchronization channel. The broadcast common-synchronization channel has a common chip-sequence signal common to the plurality of remote stations, and a frame-timing signal. The improvement includes receiving at a first RS-spread-spectrum receiver the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, and transmitting from a first RS-spread-spectrum transmitter an access-burst signal. The access-burst signal has a plurality of segments, which have a plurality of power levels.

Abstract: A system and method for encoding and transmitting data with a spread-spectrum packet-switched system. Data to be transmitted by a packet transmitter are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data is demultiplexed into sub-data-sequence signals which are spread-spectrum processed and then combined as a multichannel spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to output a packet-spread-spectrum signal which is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The multichannel spread-spectrum signal is then despread and multiplexed as received-encoded data. The received-encoded data is decoded by the intended recipient and stored in a receiver memory for output.

Abstract: In a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, mobile stations initially seek access to a selected one of two or more groups of common packet channels (CPCHs) serviced through a base station. A second order collision resolution phase, conducted between the base stations and contending mobile stations, serves to allocate one or more available channels from the selected group of channels among the contending mobile stations. In the collision resolution phase, each mobile station randomly selects a collision detection (CD) signature and sends that signature in a CD preamble. For each available channel in the group, the base station assigns one of the mobile stations. For each assigned mobile station, the base station transmits a CD acknowledgement that corresponds to the CD preamble of the assigned mobile station and identifies the available channel assigned to that mobile station.

Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal, which includes a plurality of RS-preamble signals, RS-power-control signals, and RS-pilot signals, respectively, transmitted in time, at increasing power levels.

Abstract: A superior and scaleable architecture for implementing a large bit matched filter. The implementation of the bit matched filter requires less silicon and consumes less power as compared to the existing design. An effective way to turn the bit matched filter on and off for power saving is also disclosed.

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 code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access burst signal, which includes a plurality of RS-preamble signals, RS-power-control signals, and RS-pilot signals, respectively, transmitted in time, at increasing power levels.

Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal. The BS-spread-spectrum transmitter, responsive to the BS-spread-spectrum receiver receiving the access-burst signal, transmits an acknowledgment signal.

Abstract: A subsystem and method for combining a spread-spectrum signal arriving from a plurality of paths. A header-matched filter detects each match of a header-chip-sequence signal with a first impulse response and, in response to the detection, outputs a header-detection signal having a header amplitude and a respective chip location. A data-matched filter detects, at the respective chip location of each header-detection signal, a respective data-chip-sequence signal and outputs a data-detection signal having a data amplitude. A combiner multiplies the header amplitude of each header-detection signal and the data amplitude of the respective data symbol to generate a plurality of weighted elements for each data symbol. The combiner then adds the plurality of weighted elements for each data symbol as a sum signal of the respective data symbol.

Abstract: A multi-channel spread-spectrum system separates a data stream, for example from a convolutional encoder and an interleaver, into sub-channel data-sequence signals. For each sub-channel data-sequence signal, m bits are translated to one code of a unique set of orthogonal chip-sequence signals. The other k bits of the same sub-channel data-sequence signal are translated to a distinct phasor. Each phasor is used to modulate the respective chip-sequence signal. A complex-signal combiner combines the real and imaginary components of all the phase-modulated chip-sequence signals into in-phase (I) and quadrature (Q) spread-spectrum multi-channel signals, which are spread by a cell-site specific signature-sequence. The receiver decorrelates the received spread-spectrum signal, preferably with a bank of matched filter (MF) joint-detectors, to recover the bits from all the spread-spectrum sub-channel signals for remultiplexing into the transmitted data stream.

Abstract: A multi-channel spread-spectrum system separates a data stream, for example from a convolutional encoder and an interleaver, into sub-channel data-sequence signals. For each sub-channel data-sequence signal, m bits are translated to one code of a unique set of orthogonal chip-sequence signals. The other k bits of the same sub-channel data-sequence signal are translated to a distinct phasor. Each phasor is used to modulate the respective chip-sequence signal. A complex-signal combiner combines the real and imaginary components of all the phase-modulated chip-sequence signals into in-phase (I) and quadrature (Q) spread-spectrum multi-channel signals, which are spread by a cell-site specific signature-sequence. The receiver decorrelates the received spread-spectrum signal, preferably with a bank of matched filter (MF) joint-detectors, to recover the bits from all the spread-spectrum sub-channel signals for remultiplexing into the transmitted data stream.

Abstract: In a cellular spread-spectrum communications network, a system and method for handing off a remote station from a source-base station to a target-base station without loss of data. The remote station receives a first spread-spectrum signal having a first signal quality from the source-base station and transmits data to the source-base station at a first data rate and a first power level. Responsive to monitoring the first signal quality and comparing the first signal quality to a plurality of signal qualities of a respective plurality of received-spread-spectrum signals, the remote station initiates handoff when any of a number of predetermined criteria are met. Upon initiating handoff to the target-base station, the remote station stores the data that would otherwise have been transmitted.

Abstract: A sectorized smart antenna system includes multiple sector antennas with a software control algorithm for flexible association of physical antennas to a logical serving sector to provide signal coverage in a particular region of the cell served by the base station. The control algorithm can adapt to different situations without requiring any, or only very limited, physical hardware changes to reconfigure a base station to balance the traffic load throughout the cell. The smart antenna system and method includes measuring and recording a mobile station's signal strengths and its rate of changes received by an antenna in a serving sector relative to other antennas in either the same serving sector or different serving sector to determine the mobile station location and its movement, determining when a threshold signal level is reached, and handing-off the mobile station to an adjacent antenna, serving sector, or cell.

Abstract: A spread-spectrum-phase-locked-loop apparatus and method for coherent detection without a pilot channel. The system comprises symbol-matched means, a voltage-controlled oscillator (VCO), a first product device, a second product device, a third product device, a fourth product device, a first combiner, a second combiner, and a fifth product device. The method comprises the steps of despreading, from a received spread-spectrum signal, an in-phase component and a quadrature-phase component of a symbol sequence signal using the symbol-matched means. The first and second product devices multiply the despread in-phase component by the VCO-cosine and the VCO-sine signals, respectively, to generate a first and a second product signal. The third and fourth product devices multiply the despread quadrature-phase component by the VCO-sine and the VCO-cosine signals, respectively, to generate a third and a fourth product signal.

Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal. The BS-spread-spectrum transmitter, responsive to the BS-spread-spectrum receiver receiving the access-burst signal, transmits an acknowledgment 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: A system and method for handing off a remote unit from a first base station to a second base station, in a cellular spread-spectrum communications network, without loss of data. The remote unit transmits data to the first base station at a first data rate, and receives a first spread-spectrum signal having a first signal quality from the first base station. The remote unit monitors the first signal quality and compares the first signal quality to a plurality of signal qualities of a respective plurality of received-spread-spectrum signals. The remote unit initiates handoff when any of a number of predetermined criteria are met. Upon initiating handoff to the second base station, the remote unit stores the data that would otherwise have been transmitted. Once handoff is complete, the remote unit transmits the stored data to the second base station at a second data rate, with the second data rate greater than the first data rate.

Abstract: A two-step automatic-gain-control (AGC) loop for use with a receiver. An AGC amplifier amplifies a received signal. From an output signal from the AGC amplifier, a received-signal-strength-indicator (RSSI) circuit generates an RSSI signal proportional to a received-signal-power level of the received signal. An RSSI-mapping circuit has an RSSI-mapping table. From the RSSI signal, the RSSI-mapping circuit, using the RSSI-mapping table, generates an AGC signal. An AGC-storing circuit stores the AGC signal. The AGC amplifier uses the stored-AGC signal to adjust the AGC gain. A converter circuit converts the output signal from the AGC amplifier to an in-phase component and a quadrature-phase component at a processing frequency. The error circuit determines an error signal from the in-phase component and the quadrature-phase component.

Abstract: A system and method for encoding and transmitting data with a spread-spectrum time-division-multiple-access (SS-TDMA) system. Data to be transmitted by a SS-TDMA transmitter are sent within a particular specified group of time slots. Random packets also can be sent by transmission during an open time slot. The TDMA data are demultiplexed into sub-data-sequence signals, each of which are spread-spectrum processed and then combined as a multichannel, BPSK, QPSK or QAM spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to output a packet-spread-spectrum signal which is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The multichannel spread-spectrum signal is then despread and multiplexed as received-TDMA data. The received-TDMA data are selected from a particular time slot by the intended recipient and stored in a receiver memory for output.

Abstract: A spread-spectrum-phase-locked-loop apparatus and method for coherent detection without a pilot channel. The system comprises symbol-matched means, a voltage-controlled oscillator (VCO), a first product device, a second product device, a third product device, a fourth product device, a first combiner, a second combiner, and a fifth product device. The method comprises the steps of despreading, from a received spread-spectrum signal, an in-phase component and a quadrature-phase component of a symbol sequence signal using the symbol-matched means. The first and second product devices multiply the despread in-phase component by the VCO-cosine and the VCO-sine signals, respectively, to generate a first and a second product signal. The third and fourth product devices multiply the despread quadrature-phase component by the VCO-sine and the VCO-cosine signals, respectively, to generate a third and a fourth product signal.