Abstract: In the present invention, the slave base station attains synchronization with the reference base station through messages transmitted from and received by a mobile station in the soft handoff region between the reference base station and the slave base station. First, the round trip delay between the mobile station and the reference base station is measured by the reference base station. Once the mobile station acquires the signal from the slave base station, it measures and reports the difference between the amount of time it takes a signal to travel from the reference base station to it and the amount of time it takes a signal to travel from the slave base station to it. The last measurement necessary is a measurement by the slave base station of the time difference between the time it received the reverse link signal from the mobile and station the time it transmitted a signal to the mobile station.

Abstract: A method and apparatus for providing soft handoff in a mobile communication system. In current systems is that the members of active set are determined in accordance with comparisons of measured pilot energy with fixed thresholds. However, the value of providing a redundant communication link to a mobile station depends strongly on the energy of other signals being provided to the mobile station. In the present invention, the signal strengths of other base stations in communication with a mobile station are considered when determining whether adding a base to that set of base stations in communication with the remote station is of sufficient value to justify the impact on system capacity.

Abstract: A method and apparatus for variable rate communication incorporating coherent signal processing and combining is described. Within the receive system, vectors of in-phase and quadrature-phase Walsh correlator output values are generated for each Rake finger over each Walsh symbol period. In-phase and quadrature-phase reference values are generated for each of the Rake fingers by combining the in-phase and quadrature-phase correlator outputs of the most likely Walsh symbols over a series of Walsh symbol periods. The output energies are calculated as the sum of squared in-phase and quadrature-phase values. The vectors of in-phase and quadrature-phases values are then projected on the in-phase and quadrature-phase reference values and weighted by the reference amplitude. The reference amplitude is the square root of the sum of squared in-phase and quadrature-phase values.

Abstract: In a half-duplex communication system in which additional delays in the communication channel may cause a message collision between a message and a response, a timer based collision prevention circuit is utilized to prevent the message collision. The collision prevention circuit determines if the message transmitted by a communication device will be repeated. If the message is to be repeated, the collision prevention circuit sets a countdown collision timer to a predetermined period of time shorter than the shortest repetition interval of the repeated message. A response is only sent to the communication device if the collision timer has not expired. If the timer expires, the collision prevention circuit waits for the message to be retransmitted by the source device before sending the response to the communication device.

Abstract: A method and apparatus for controlling transmission power in a mobile communication system is disclosed. The method disclosed provides for a closed-loop power control method for variable rate transmissions. The power of transmissions is varied in accordance with the rate of the frames of data being transmitted. The transmission power between the rates can be a fixed or variable difference.

Abstract: A system and method for providing subscriber unit or base station initiated service negotiation in a wireless communication system. Message generators in the mobile switching center, base station, and subscriber unit compose messages to be transmitted in association with the service negotiation, while message processors analyze received messages in order to direct the message generators to compose the appropriate response messages. In a subscriber unit initiated service negotiation, the subscriber unit initiates service negotiation by sending a Service Request Message to the base station containing the requested service configuration. The base station then checks with the mobile switching center to ensure that the requested service configuration is authorized for use by the particular subscriber unit.

Abstract: A method and apparatus for encoding and decoding QAM trellis modulated data. In the transmitter, a subset of bits of an input bit set are convolutionally encoded based upon a punctured convolutional code of a lower data rate to provide a set of coded symbols. The coded symbols and the uncoded bits of the input bit set are provided to a QAM modulator to provide a QAM modulation signal indicative of the values of coded symbols and the uncoded bits. In the receiver a QAM demodulator converts the received QAM signal to QAM signal space coordinates. A decoder employing the Viterbi algorithm is used to reconstruct a corrected estimate of the values of the coded data bits from the received signal coordinates. The corrected estimate of the values of the coded data bits are then used in conjunction with the received signal coordinates to provide corrected estimates of the values of the uncoded input bits.

Abstract: A system for displaying performance characteristics of a circuit in a telecommunications network. The system is adapted for use with a CDMA telecommunications network and includes a Markov call testing system for performance testing the telecommunications circuit. A computer stores the results of the performance test. Software running on the computer determines a subset of the results sufficient to reflect the performance of the telecommunications circuit. A monitor on the computer displays information corresponding to the subset. In the illustrative embodiment, the system further includes a method for determining if one or more receive antennas in the telecommunications network are balanced. The telecommunications circuit corresponds to a cell site modem chip in a base station. The subset includes a number of finger signal peaks. The number is determined by calculations performed on a scan set to determine a floor above which signal peaks are chosen for inclusion in the subset.

Abstract: The transmitted power of a mobile telephone is established by power control bits that are transmitted in a traffic channel from a base station and that are demodulated by a rake receiver in the telephone. The rake receiver includes a plurality of demodulators that demodulate respective fingers of the traffic channel which may be caused by multipath conditions, with the power control bits from each demodulator being combined with the power control bits of the other demodulators in the rake receiver regardless of whether the demodulators are in lock with their respective fingers. The combined power control signal from a rake receiver associated with a first base station is then tested against a threshold. If the combined power is at least equal to the threshold, the combined power control signal is sent to a logic combiner. If other base stations are communicating with the mobile telephone, the combined power control signal from each of these other base stations is also sent to the logic combiner.

Abstract: A method and apparatus for decoding a frame of multi-rate encoded digital data which contains redundant information provided to validate the decoding operation. A frame of data is received which contains information bits and cyclic redundancy check (CRC) bits. In accordance with the invention, the received frame is decoded and a check is conducted to determine whether the CRC bits correspond correctly for the decoded information bits. If the decoded frame passes the CRC test process, the decoded fame is provided to the user. However, if the decoded frame does not pass the CRC test, then at least one additional decoding process is performed on the received frame. In the first exemplary embodiment of the present invention, on a failure of the CRC check, the data is decoded using a trellis decoder and the data that yields the next most likely path through the trellis is selected.

Abstract: The present invention provides a method and apparatus for providing improved quality or power control by recognizing the delays inherent in a closed-loop communication system. The mobile station or receiver properly adjusts its forward link quality or power level thresholds or measurements with which it compares incoming frames or portions thereof to reflect the level it anticipates receiving (after the delay). For example, the mobile station can recognize that at a given measurement time, two outstanding messages have not been executed by the transmitter (where each message indicates a corresponding increase of 1 dB). As a result, the mobile station can adjust its measurement threshold down by 2 dB to more closely correspond to future power adjustments. If the currently received frame or portion thereof is still below the readjusted threshold, then the mobile station sends out a new message to request a further increase in the forward link channel.

Abstract: In a communications system, a method of transforming a set of message signals representing a message comprising the steps of first encoding one of the set of message signals in accordance with a first keyed transformation, a second encoding of the one of the set of message signals in accordance with at least one additional keyed transformation, a third encoding of the one of the set of message signals in accordance with a self inverting transformation in which at least one of the set of message signals is altered, a fourth encoding of the one of the set of message signals in accordance with at least one additional inverse keyed transformation wherein each of the at least one additional inverse keyed transformation is a corresponding inverse of at least one additional keyed transformation, and fifth encoding the one of the set of message signals in accordance with first inverse keyed transformation wherein the first inverse keyed transformation is the inverse of the first keyed transformation.

Abstract: A voice mail system is provided in a CDMA wireless telephone system in which a base station controller (BSC) stores, in a encoded format, voice data transmitted by a wireless telephone to a receiving telephone, either wireless or fixed telephone, when the receiving telephone does not "pick up". Also, the base station controller encodes and then stores voice data that is transmitted by a fixed telephone to a wireless telephone when the wireless telephone does not "pick up". In either case, to retrieve voice mail the intended recipient can access the voice mail from a fixed telephone, in which case the voice mail is decoded at the BSC and then sent to the fixed telephone via a landline. Alternatively, the intended recipient can access the voice mail from a wireless telephone in the system, in which case the voice mail is not decoded at the BSC, but is transmitted directly to the wireless telephone, where the message is decoded.

Abstract: The present invention provides a method and apparatus for allowing a base station or base station controller to adjust transmissions to fixed location subscribers in closed-loop communication systems. In a closed-loop communication system, a base station exchanges signals with both fixed location and mobile user stations. When a user or subscriber initially registers with the base station, the base station determines a status of this subscriber based on, for example, an electronic serial number transmitted to the base station. The base station compares the electronic serial number to a database (Home Location Register) which determines whether the user corresponds to a fixed station or a mobile station. If the user is a fixed station, then the base station lowers nominal and minimum power level thresholds. Based on the lowered thresholds, the base station thereafter transmits forward link signals to the fixed station at a lower power level.

Abstract: The present invention employs a method and apparatus for providing improved power control when changing the rate at which data is sent in a communications system. When data arrives at the transmitter for transmission at a high rate, power control feedback is changed from a slow mode (with a low bandwidth feedback channel) to a fast mode (with a high bandwidth feedback channel). This control changes even before the data is transmitted at the high rate. Once the power level is accurately estimated for data transmission at the high rate, then data transmission begins at the high rate.

Abstract: The present invention is a novel and improved method and apparatus for transmitting and receiving code division multiple access (CDMA) signals. In a described embodiment of the invention, the radio frequency (RF) signals are received through a first polarization RF unit and a second polarization RF unit generating right slant samples and left slant samples. The right slant samples and the left slant samples are each searched and multipath processed independently and the resulting sets of soft decision data combined and decoded. In a preferred embodiment of the invention, right slant and left slant instances of the signal are generated and transmitted to increase the likelihood of differently polarized instances of the signal being available at the receive system.

Abstract: A method and apparatus for controlling transmission power in a mobile communication system, which provides for a closed-loop power control method. A mobile station provides information on the quality of the signal received from the base station, and the base station responds by adjusting the power allocated to that user in a shared base station signal. The transmission power is adjusted initially by a large increment and then ramped down at an increasingly decreasing rate. The mobile station also provides information to the base station as to its relative velocity and the base station adjusts its transmission power in accordance with this velocity information.

Abstract: A method for determining the position of a mobile station within a cellular telephone system having first and second base stations. A round trip signal propagation time between the first base station and the mobile station is measured at the first base station. A first signal is transmitted from the first base station to the mobile station, and a second signal is transmitted from the second base station to the mobile station. An arrival time difference representing a time interval between a first relative time when the first signal is received at the mobile station and a second relative time when the second signal is received at the mobile station is measured at the mobile station. The position of the mobile station is determined in accordance with the round trip propagation time and the arrival time difference.A method for determining the position of a mobile station within a cellular telephone system having first and second base stations.

Abstract: A method and apparatus which permits handoffs while the mobile station is in the system access state. This is achieved by providing for channel assignment messages to be sent over the paging channel of a plurality of base stations, which increases the probability of one of the messages getting through. In addition, this assures the mobile station will be able handoff to a different base station and have a traffic channel allocated to it on the new base station without delay. In addition, a method and apparatus which permits the mobile station to be directly assigned into a soft handoff state upon traffic channel assignment.

Abstract: A variable rate transmission system wherein a packet of variable rate data generated by a variable rate data source is modulated on traffic channel by traffic channel modulator if the capacity of the traffic channel is capable of transmitting the packet. And where the packet of variable rate data is modulated onto traffic channel by traffic channel modulator and at least one overflow channel by traffic channel modulator, if the capacity of the traffic channel is less than required to transmit the packet. A receiving system for receiving variable rate data transmitted in accordance with the above.