Abstract: A novel and improved method and apparatus for controlling signal power level in a communication system (100) is provided by determining first and second signal to interference ratios of a received signal, respectively before and after an interference cancellation, determining a difference between the first and second signal to interference ratios, and determining, based on the difference, a signal to interference threshold for controlling power level of a signal transmitted from a source of the received signal.

Abstract: An improved method and system for determining round-trip time (RTT) during a radio link protocol (RLP) wireless communication link. The RTT estimate is negotiated by both sides of the RLP communication link without the need for the 3-way handshake generally required for RLP synchronization. The method includes techniques used by both sides of the RLP communication link to dynamically update and refine their initial, negotiated RTT estimates.

Abstract: The present invention encompasses a mobile station comprising a transmitter for transmitting outgoing signals from the mobile station and a receiver for receiving incoming signals, the receiver coupled to the transmitter and having N subreceivers, where N is an integer greater than one and each of the N subreceivers may independently be tuned to a desired frequency.

Abstract: A method for minimizing search time and disruption of current service on an originating frequency during a frequency search excursion to a target frequency as part of an inter-frequency hard handoff between cells on different RF CDMA channels. In one embodiment, the method for minimizing search time includes tuning a selected mobile station to a target frequency and collecting chip samples, which are stored in a memory buffer, but not performing pilot searches and pilot strength measurements while on the target frequency; tuning the selected mobile station back to the original frequency and simultaneously resuming reception of forward link and transmission of reverse link and processing the samples collected on the target frequency to calculate pilot strength measurements from the target frequency.

Abstract: A predistortion technique for high power amplifiers includes an adaptive predistortion algorithm that operates independently of data samples to write a set of complex gain values, or predistortion parameters, to a lookup table. The algorithm may be processor-driven. The gain values are taken from the lookup table and multiplied by a complex digital baseband waveform. The gain values may first be subjected to interpolation. The downconverted output of the amplifier is measured to gauge the efficacy of the predistortion. Based on the effect of the predistortion upon the ratio of in-band power to out-of-band power, decisions are made on the set of predistortion parameters for the next iteration of the algorithm. The algorithm runs continuously, perturbing parameters and adapting the predistortion functions accordingly in an effort to continually reflect instantaneous amplitude-modulation and phase-modulation relationships that may change over time with temperature variation or component aging.

Abstract: A system and method for selectively muting a call of a wireless communication system. A first predetermined signal is received by the wireless communication system. The phone signal has a user signal associated with it. In response to the first predetermined signal, the wireless communication system pauses communication of the user signal to the end user while still maintaining the phone call between the wireless communication system and the conference bridge. In response to a second predetermined signal, the wireless communication system reiates communication of the user signal to the end user.

Abstract: A method and apparatus for efficient candidate frequency search while initiating a handoff in a code division multiple access communication system. The method includes when the pilot signal is transmitted by the mobile station that is power controlled to a target receive level, the traffic channel power level is increased relative to the pilot channel to improve receiver performance. An improved feature is that the received pilot received at the base station stays the same while the receiver receives extra energy in the redundant traffic symbols received to enhance the probability of correctly decoding the received frame. The base station detects the absence of the mobile station transmitted signal from the frequency of interest. If the base station is aware of the starting time and duration of the absence, it can focus its detection during this predetermined time period. The performance can be improved if the absence of the signal is spread across two frames at the frame boundary.

Abstract: A priority access channel assignment system and a messaging protocol allow wireless mobile stations to place calls having differing priority levels. A mobile station originates a call, which may automatically include a request for priority access or may require manual intervention by the user to request priority access. If system resources are unavailable to process the call immediately, the origination message is processed by a base station and a mobile switching center using a plurality of messaging protocols to determine the time at which the call was originated and a priority level associated with the call. Based on the priority level and arrival time, the base station places the call in an appropriate position within a queue. Higher priority calls are placed in a higher position in the queue than lower priority calls. Calls having identical priority are placed in the queue in order of the time of arrival.

Abstract: A method and apparatus for computing soft decision input metrics to a turbo decoder includes circuits associated with eight-ary phase shift keyed (8PSK) modulation and sixteen-ary quadrature amplitude modulation (16QAM). In both implementations log-likelihood ratio (LLR) metrics on code symbols are estimated as products of various constant values and various combinations of the in-phase and quadrature components of a demodulated soft decision. In the implementation associated with the 16QAM modulation scheme, an estimate of the carrier-signal-to-interference (C/I) ratio is also used to estimate some of the LLR metrics. Estimates of the LLR metrics may also be obtained in association with generalized square QAM and M-ary PSK modulation schemes including, e.g., 64QAM, 256QAM, and 16PSK.

Abstract: When insufficient traffic is present in the network to maintain synchronization in this manner, other methods must be used. One approach involves making direct measurements of the timing between base stations. This is accomplished in one of two ways. The base may interrupt its transmissions on all sectors for a short interval during which it determines the time of arrival of signals from other base stations. Given knowledge of the other base station locations, time errors relative to all other base stations may be derived. Alternatively, the base may send a short signal at high power in the mobile transmit band. This time-of-arrival of this signal is measured by the surrounding base stations and the time errors between pairs of base stations are computed. In some cases, a base station may be isolated sufficiently from all other base stations in the network such that direct base-to-base measurement is not viable.

Abstract: A mobile station transmits a plurality of channels including a pilot channel and at least one information channel. In the exemplary embodiment, the base station determines the adequacy of the transmission energy of the reverse link signal in accordance with the received energy of the reverse link pilot signal. In the present invention, the pilot channel transmission power is retained at the level it was prior to the frequency search excursion, while increasing the transmission energy of at least one other channel transmitted by the mobile station. In addition, when the mobile station is not capable of increasing the transmission energy of all of the information channels, the mobile station generates a ranking of the importance of the different information channels and selectively increases the transmission power of those channels.

Abstract: A novel and improved method for implementing a high-transmission-rate over-the-air interface is described. A transmit system provides an in-phase channel set and a quadrature-phase channel set. The in-phase channel set is used to provide a complete set of orthogonal medium rate control and traffic channels. The quadrature-phase channel set is used to provide a high-rate supplemental channel and an extended set of medium rate channels that are orthogonal to each other and the original medium rate channels. The high-rate supplemental channel is generated over a set of medium rate channels using a short channel code. The medium rate channel are generated using a set of long channel codes.

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: Access to a variable rate multiple access system is controlled based upon a current loading. The current loading level is used to determine a transmission rate set point. The transmission rate set point may include a maximum transmission rate and a transmission probability. The transmission rate set point is passed to the remote unit which may access the system. A remote unit with data to send determines a desired transmission data rate. If the desire transmission data rate is equal to or greater than the maximum transmission data rate, the remote unit transmits at the maximum transmission data rate with a probability equal to the transmission probability.

Abstract: A method of supervising on the forward link in a high data rate system is disclosed, wherein a base station transmits to an access terminal on a forward traffic channel only when the base station has data to send to the access terminal. The base station minimizes the worst-case period necessary to reclaim traffic channel resources following a release by periodically transmitting a configuration packet to its access terminals. The configuration packet indicates the allocation status of the traffic channels belonging to the base station. If an access terminal receives a configuration packet indicating the deallocation of one or all of its traffic channels, the access terminal immediately ceases its use of those traffic channels. If an access terminal fails to successfully decode a configuration packet for a predetermined supervision time, the access terminal releases its connection with all base stations and associated traffic channels.

Abstract: Method and apparatus for performing transmission data rate allocation in a high speed wireless communications network. A macro control loop with the network of base stations on one side and all the subscriber stations on the other side. Subscriber station selects a rate based on the amount of data queued for transmission (100). Adjusts this rate based on the available power headroom of the subscriber station (102). This adjusted transmission rate is then adjusted again to account for protection of base stations in the candidate set of the subscriber station (104). This rate is then adjusted in accordance with busy tone signals indicative of the loading conditions of active set base stations of the subscriber station (108). The base stations react to these action by refreshing measurements of their instantaneous traffic load and providing feedback in the form of soft busy tones. The algorithm is named Closed Loop Resource Allocation.

Abstract: An apparatus and method for echo cancellation is presented. The echo canceller comprises an adaptive filter that tracks the impulse response of the echo path and produces an estimate of the echo. Filter adaptation is controlled by a controller based on the rate of the far-end speech signal, the rate of the near-end signal, an acoustic loss measure, and a double talk hangover indicator. The controller may also comprise a step size adaptation unit for determining the adaptation step size of the adaptive filter. In addition, the controller may comprise a noise replacement unit, which controls replacement of the echo residual signal with comfort noise to ensure echo is completely rejected when only the far-end speaker is talking.

Abstract: A method and apparatus for controlling a data rate associated with the transmission of information from a base station to a mobile station in a mobile radio communication system. The mobile station alternately receives information from a base station either in a variable rate mode or a fixed rate mode. The transmission rate from a base station in the variable rate mode varies between successive data transmit intervals, and the transmission rate from a base station in the fixed rate mode remains fixed between successive data transmit intervals. Data is transmitted from a first base station to the mobile station in the variable rate mode until the first base station is unable to receive variable data rate control information from the mobile station.

Abstract: Embodiments of a planar antenna suitable for use with a portable device for wireless communications are described. One such embodiment includes a microstrip line coupled to a radiating poise on one side of a circuit board, and a ground plane coupled to a structure on the other side of the circuit board that functions as a coplanar waveguide having an effective length of one quarter-wavelength. A further implementation includes a transformer portion configured and arranged to match the impedance of an RF signal source to the antenna driving impedance.

Abstract: Reverse link busy bits are independently generated by each base station and indicative of whether the transmitting base station has reached a reverse link capacity limit. In a first exemplary embodiment, the remote station combines the multipath components of the reverse link busy bits from each of the transmitting base stations in its Active Set and in response transmits a reverse link signal only when all of the reverse link busy bits indicate that the base stations in the remote stations Active Set have reverse link capacity. In a first alternative embodiment, the remote station weights the reverse link busy signals in accordance with the signal strength of the base station transmitting the busy signal and determines whether to transmit based on the weighted sum of the busy signals.