Abstract: A method and system for rapidly acquiring a spreading code, used in a code division multiple access (CDMA) system. A first long code and a second long code, with each long code having a length of N chips, are generated. The first long code is different from the second long code. The first long code and the second long code are transmitted at a first phase angle and at a second phase angle, respectively, on a carrier signal, over a communications channel using radio waves. The first long code and the second long code may be transmitted at an in-phase (I) angle and at a quadrature-phase (Q) angle, respectively, on the carrier signal. From the communications channel, an I-phase acquisition circuit and a Q-phase acquisition circuit may acquire, in parallel, the first long code and the second long code from the I-phase angle and the Q-phase angle, respectively, of the carrier signal by searching, in parallel, N/2 chips, the first long code and the second long code.

Abstract: A spread spectrum base station comprises an automatic gain control (AGC) circuit having an input configured to receive a received spread spectrum signal and gain control the received spread spectrum signal to produce a gain controlled signal. A correlation circuit has an input configured to receive the gain controlled signal and correlate the gain controlled signal with a code to produce a despread signal. A power measurement and comparator circuit is configured to receive the despread signal and a control level of the AGC circuit. The circuit processes at least the despread signal and the control level to produce a processed signal and compares the processed signal with a threshold to produce a comparison signal. The comparison signal is used to produce a power command. A multiplexer multiplexes the power command with a signal for transmission over an antenna.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

Abstract: A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller is coupled to receive a remote call.

Abstract: A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Abstract: A subscriber unit for use in a multiple access spread-spectrum communication system includes a spread spectrum radio interface, responsive to a rate function signal from a base station, and first and second despreaders. The base station assigns the rate function spread-spectrum message channels and the first despreader recovers and modifies an information signal one of the spread spectrum message channels. The information channel mode is then modified for processing by the second despreader, with the second despreader supporting a different information signal rate. The subscriber unit has a capability of communicating with a dynamically changing a transmission rate of an information signal which includes multiple spread spectrum message channels.

Abstract: A spread spectrum system having an assignor, a spread-spectrum processor and a transmitter. The assignor assigns each arriving information signal to a message-code signal. Each message-code signal is different then other message-code signals. The spread-spectrum processor generates a pilot code signal and processes the information signals with the message-code signals to generate spread-spectrum process-message signals synchronized to the pilot-code signal. A transmitter combines the spread-spectrum process-message signals and the pilot-code signal to generate a CDM signal. The transmitter modulates the CDM signal with a carrier signal for transmission over the communications channel.

Abstract: A spread-spectrum system having an assignor, a spread-spectrum processor, a call processor, and an information-channel-mode modifier. The assignor assigns each information signal arriving at the spread-spectrum system to a message-code signal. Each of the message-code signals supports a pre-determined information-channel rate. Several information signals have different channel rates, and each information signal is assigned according to the required channel rate. The spread-spectrum processor generates a pilot-code signal, and spread-spectrum processes the information signals with the message-code signals to generate a plurality of spread-spectrum processed-message signals, respectively. The message-code signals are synchronized to the pilot-code signal. The call processor provides a call-type signal corresponding to the information signal rate for the several information signals having several different channel rates.

Abstract: A spread spectrum signal having an associated code is tracked at a receiver. A plurality of components of the spread spectrum signal are despread using the associated code. Each of the plurality of components has a different code phase than all others of the plurality of code phases. Each of the plurality of components is weighted based on a phase difference between that component and a center code phase associated with the plurality of components. A tracking error is determined based on the weighted components.

Abstract: A device tracks multipath components of a spread-spectrum signal. The spread-spectrum signal has an associated chip code sequence. The device receives multipath components of the spread-spectrum signal. A first and second plurality of multipath components are despread about a center code phase. The first plurality is a sequence of multipath components prior to the center code phase and the second plurality is a sequence of multipath components after the center code phase. A first and second combined energy is determined from the first and second plurality of multipath components. A tracking delay is calculated based on a difference between the first and the second combined energies. The center code phase is adjusted by said tracking delay.

Abstract: A code transmitted in a wireless format is to be detected. A power level associated with the code is determined. The determined power level is compared with a plurality of thresholds. A test statistic is increased or decreased based on which of the thresholds that the determined power level falls within. If the test statistic exceeds an acceptance threshold, the code is deemed acquired. If the test statistic is below a dismissal threshold, the code is deemed not present. If the test statistic does not exceed the acceptance threshold and the test statistic is not below the dismissal threshold, the testing for the code is repeated.

Abstract: A method and apparatus for communication data signal blocking for a base radio control station (RCS) which wirelessly communicates with subscriber units (SUs) via a spread spectrum communication system is disclosed. A transmitter sends signals as a baseband combined signal over global and assigned channels to SUs. The SUs are set to initial power levels and the power levels are adjusted in advance of receiving signals on assigned channels. The power levels are combined to define an RCS transmitter power level, which is preferably a root mean square value of the baseband combined signal. The transmission power levels are adjusted in response to corresponding power control signals received from the SUs. Transmission of a new communication data signal on an assigned channel is blocked if a predetermined RCS transmitter power level limit is reached before commencing transmission of that signal.

Abstract: A subscriber unit (SU) transmitter transmits signals over global and assigned channels to a base station which are initialized at an initial power level and adjusted to a controlled power level in advance of transmitting a communication data signal on an assigned channel to the base station. The power level of the SU transmitter is controlled to adjust the SU transmitter power level in response to power control signals received from the base station. The SU transmitter power level is monitored in advance of transmitting a communication data signal on an assigned channel to the base station. The transmitter is controlled such that transmission of a communication data signal on an assigned channel is blocked if a predetermined power limit is reached before commencing transmission of the communication data signal on the assigned channel.

Abstract: A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller is coupled to receive a remote call.

Abstract: A spread spectrum code division multiple access communication system has a plurality of traffic channels. A plurality of traffic lights have a red state and a green state. Each traffic light is associated with a traffic channel. The state of each traffic light is based on an availability of that traffic light's associated traffic channel. The base station broadcasts each traffic light over a broadcast channel.

Abstract: A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Abstract: A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Abstract: A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Abstract: A device tracks multipath components of a spread-spectrum signal. The spread-spectrum signal has an associated chip code sequence. The device receives multipath components of the spread-spectrum signal. A first and second plurality of multipath components are despread about a center code phase. The first plurality is a sequence of multipath components prior to the center code phase and the second plurality is a sequence of multipath components after the center code phase. A first and second combined energy is determined from the first and second plurality of multipath components. A tracking delay is calculated based on a difference between the first and the second combined energies. The center code phase is adjusted by said tracking delay.

Abstract: A multiple access, spread-spectrum communication tracking system includes apparatus which tracks a centroid of a transmitted code-division multiplexed (CDM) code sequence that is contaminated with multipath distortion. The apparatus includes an analog to digital converter which digitally samples the spread-spectrum channel signal to produce a sequence of sample values. The sample values are divided into a set of even-numbered sample values which correspond to early multipath signal components and the set of odd sample number values which correspond to the multipath signal components. The centroid tracking receiver generates a plurality of local code sequences, each of which is a code phase-shifted version of the transmitted code sequence. The centroid tracking receiver correlates each of the locally generated code sequences with the odd and even numbered sample values, respectively, to produce a group of early despread multipath signals and a group of late despread multipath signals.