Abstract: In a data communication system capable of variable rate transmission, high rate packet data transmission improves utilization of the forward link and decreases the transmission delay. Data transmission on the forward link is time multiplexed and the base station transmits at the highest data rate supported by the forward link at each time slot to one mobile station. The data rate is determined by the largest C/I measurement of the forward link signals as measured at the mobile station. Upon determination of a data packet received in error, the mobile station transmits a NACK message back to the base station. The NACK message results in retransmission of the data packet received in error. The data packets can be transmitted out of sequence by the use of sequence number to identify each data unit within the data packets.

Abstract: Operating a communication device in a half-duplex mode using only overhead channels; and substantially free running a timing reference obtained during reception to allow a timing reference value to drift during transmission.

Abstract: A method and apparatus are described for controlling the data rates for communications to and from a base station and a plurality of remote users. The usage of the communications resource whether the forward link resource (from base station to remote users) or reverse link resource (from remote users to base station) is measured. The measured usage value is compared against at least one predetermined threshold value and the data rates of communications or a subset of communications on said communications resource is modified in accordance with said comparisons.

Abstract: In a high data rate communication system, a method and apparatus for improved throughput while transmitting data packets within multiple time slots. In order to avoid unnecessary retransmissions of a packet, a subscriber station sends a Stop-Repeat signal to a base station, causing the base station to cease further transmissions of the packet. In order to enable successful decoding of a packet, a subscriber station sends a Continue-Repeat signal to a base station, causing the base station to send retransmissions of the packet during time slots beyond a predetermined default number of time slots.

Abstract: In a data communication system capable of variable rate transmission, high rate packet data transmission improves utilization of the forward link and decreases the transmission delay. Data transmission on the forward link is time multiplexed and the base station transmits at the highest data rate supported by the forward link at each time slot to one mobile station. The data rate is determined by the largest C/I measurement of the forward link signals as measured at the mobile station. Upon determination of a data packet received in error, the mobile station transmits a NACK message back to the base station. The NACK message results in retransmission of the data packet received in error. The data packets can be transmitted out of sequence by the use of sequence number to identify each data unit within the data packets.

Abstract: A system and method is taught for controlling a power level of transmissions in a communication system. A first station of the communication system transmits signals on a communication channel and a pilot channel. A second station of the communication system measures a signal to noise ratio of the received signal, determines an expected signal to noise ratio of the received signal, determines an indicator in accordance with said measured signal to noise ratio and the expected signal to noise ratio, and transmits the indicator. The indicator is received at the first station the indicator and determines the power level of the next transmission according to said received indicator. Additionally, methods and systems for the measurement of the signal to noise ratio of the received signal, the determination of the expected signal to noise ratio of the received signal, and the determination of the indicator are disclosed.

Abstract: For determining use of receive diversity in a mobile station, a control system (210 or 401) determines a demand level for use of communication resources. A transmitter (300) communicates a message indicating use of receive diversity at a mobile station based on the determined demand level. In another aspect, a receiver (200) receives a channel and determines transmit power level of the channel for being at a lower or upper transmit power level limit. The control system (210 or 401) controls receive diversity by selecting a number of receiver chains (290) based on the determined transmit power level. In another aspect, receiver (200) receives a channel and determines a channel condition of the channel and duration of the channel condition. Control system (210 or 401) controls receive diversity by selecting a number of receiver chains (290) based on the determined channel condition and the duration.

Abstract: Collisions between messages simultaneously transmitted by multiple spread-spectrum transmitters are reduced by distributing the transmissions over the available resources of the receiver. Each mobile station in a CDMA system uses one or more randomization methods to distribute its transmissions. In the first randomization, the mobile station time-delays its transmissions by a number of chips of the PN code with which it spreads the transmitted signal. In a second randomization, the mobile station randomly selects the PN code. In a third randomization, the mobile station inserts a random delay between successive message transmissions or probes if it does not receive an acknowledgement after a predetermined timeout period. A predetermined number of such transmissions is called a probe sequence. In a fourth randomization, the mobile station inserts a relatively long random delay between successive probe sequences if it does not receive an acknowledgement of any probe in the sequence.

Abstract: A method and apparatus for controlling transmission power levels in a mobile communication system. The method 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 system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the exemplary embodiment, transmit power of mobile unit signals is controlled based on signal power received by the mobile unit and power adjustment commands sent to the mobile unit.

Abstract: A system and method for assembling a single data stream from multiple instances of that data stream is described. Data transmitted from a cellular telephone subscriber unit is received by a set of base transceiver stations. Each base transceiver station performs various error detection procedures on segments of the data referred to as frames. These error detection procedures may include CRC check sum verification, Yamamoto metric calculation, re-encoded signal error rate calculation, or a combination thereof. The results of these error detection procedures are placed into a frame quality metric. The frame, frame quality metric, a time stamp and an address are placed into a packet that is transmitted from each base transceiver station to a base station controller which matches packets attempting to transmit the same information using the time stamp and selects one frame from the packets for further processing based on the associated frame quality metric.

Abstract: A method and apparatus for controlling transmission power levels in a mobile communication system. The method 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 system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.

Abstract: A method and apparatus for optimizing system parameters in a cellular communication network. Pilot strength measurement messages (PSMMs) that are received by bases stations of the network to be optimized are saved in a database. The database accumulates the raw data contained in the pilot strength measurement messages. After a sufficient amount of data has been collected, a report generator compiles a statistics report for each base station based on the raw PSMM data. The present invention then provides a method for applying the information in the report in order to optimize the network parameters of the cellular system. The neighbor list which is transmitted on the paging or traffic channel is revised in accordance with the compiled statistics. The antenna tilt of the base stations is adjusted in accordance with the compiled statistics.

Abstract: Methods and systems for estimating and canceling pilot interference in a wireless (e.g., CDMA) communication system. In one method, a received signal comprised of a number of signal instances, each including a pilot, is initially processed to provide data samples. Each signal instance's pilot interference may be estimated by despreading the data samples with a spreading sequence for the signal instance, channelizing the despread data to provide pilot symbols, filtering the pilot symbols to estimate the channel response of the signal instance, and multiplying the estimated channel response with the spreading sequence. The pilot interference estimates due to a plurality of interfering multipaths are accumulated to derive the total pilot interference, which is subtracted from the data samples to provide pilot-canceled data samples. These samples are then processed to derive demodulated data for each of at least one (desired) signal instance in the received signal.

Abstract: Collisions between messages simultaneously transmitted by multiple spread-spectrum transmitters are reduced by distributing the transmissions over the available resources of the receiver. Each mobile station in a CDMA system uses one or more randomization methods to distribute its transmissions. In the first randomization, the mobile station time-delays its transmissions by a number of chips of the PN code with which it spreads the transmitted signal. In a second randomization, the mobile station randomly selects the PN code. In a third randomization, the mobile station inserts a random delay between successive message transmissions or probes if it does not receive an acknowledgement after a predetermined timeout period. A predetermined number of such transmissions is called a probe sequence. In a fourth randomization, the mobile station inserts a relatively long random delay between successive probe sequences if it does not receive an acknowledgement of any probe in the sequence.

Abstract: A method and apparatus for controlling transmission power levels in a mobile communication system. The method 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 wireless packet data communications system that includes a number of modem pool transceivers (MPTs), one or more modem pool controllers (MPCs), and one or more servers. Each MPT receives and processes data packets to generate a modulated signal (e.g., a CDMA spread spectrum signal) suitable for transmission over a terrestrial communications link. Each MPC provides call related processing for one or more MPTs. The servers couple to the MPTs and MPCs via an Internet Protocol (IP) back-bone and provide management of the communications system. The IP back-bone further interconnects the MPTs with one or more data networks and includes a number of routers that route data packets between the data networks and the MPTs. Each MPT can couple to two or more routers for redundancy. Each MPT is operated as an element in an IP network and is associated with an IP address that identifies the MPT.

Abstract: A “time multiplexed” transmission scheme capable of reducing the amount of interference from other cells operated at the same frequency band. Each cell in a system transmits in designated time intervals (e.g., time slots) during which other interfering cells may be prevented from transmitting. By temporarily “blanking” transmissions from interfering cells during the designated time slots, the amount of interference from these cells is reduced. The improved signal quality may support transmission at a desired or higher data rate, which may not be possible without cell blanking. In one variant, transmissions from the cells are staggered over different time slots. A set of one or more cells may be designated to transmit in each of a number of slot phases. The cells transmit in a staggered manner on these phases to reduce interference. The transmission scheme may be used for a various channel types (e.g., a control channel) and applications.

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.