Abstract: Methods and apparatus for estimating mobile station location in a wireless communication system. At initiation of a call or a page response, a mobile station of the system sends an access request signal to a primary base station. The primary base station responds with an access acknowledgment which may be intentionally delayed such that the mobile station increases its transmit power level. The primary base station then transmits a channel assignment message to the mobile station. The mobile station responds by transmitting a location signal in the form of a known user-specific traffic preamble at the higher transmit power level. The primary base station intentionally delays sending an acknowledgment of the preamble, such that the mobile station transmits the preamble for a longer period of time than it would otherwise.

Abstract: A method for allocating utilization of multiple carriers in a wideband CDMA transmission system first determines the carrier utilization/interference levels for each of the multiple carriers. Based on the carrier utilization/interference level, carrier assignments are allocated on an unequal basis. The allocation of the carrier assignment biases the selection of the carriers away from higher utilized/interfered carriers. An apparatus for implementing the method is also described.

Abstract: Methods and apparatus for estimating mobile station location in a wireless communication system. At initiation of a call or a page response, a mobile station of the system sends an access request signal to a primary base station. The primary base station responds with an access acknowledgment which may be intentionally delayed such that the mo bile station increases its transmit power level. The primary base station then transmits a channel assignment message to the mobile station. The mobile station responds by transmitting a location signal in the form of a known user-specific traffic preamble at the higher transmit power level. The primary base station intentionally delays sending an acknowledgment of the preamble, such that the mobile station transmits the preamble for a longer period of time than it would otherwise.

Abstract: A procedure for triggering a handdown or a handoff a mobile station served by a base station of a cellular wireless communication system. A tolerable path loss for signal links between the base station and a mobile station located within the base station's cell, is initially determined. A control signal is radiated at a known transmit power level from the base station over its cell. A receive power level threshold is determined for the control signal for reception by the mobile station, according to the transmit power level and the tolerable path loss. A handoff of the mobile station is triggered after deriving the received power level of the control signal at the mobile station, and determining that the received power level is less than the receive power level threshold.

Abstract: A method to dynamically assign data rates, for digital data transmission in wireless communication systems, which are just sufficient to meet the needs of the use is presented. The method monitors the data traffic and anticipates when the assigned data rate is inadequate to support the data traffic resulting in a loss of data or when the assigned data rate is more than necessary to support the data traffic and results in inefficient usage of system resources.

Abstract: A base station assembles a frame including information bits at a vocoding rate for downlink transmission over a traffic channel as channel bits at a channel rate. The base station places at least one rate-indicating bit at a beginning of the frame for indicating the vocoding rate. The mobile station evaluates the downlink transmission with consideration of the vocoding rate indicated by the at least one rate-indicating bit. The mobile station can determine the vocoding rate by decoding the beginning of the frame to permit power control in less than one frame duration from initial receipt of the frame at the mobile station.

Abstract: The invention provides a novel burst duration assignment process that increases the performance and improves the throughput of communication systems. In particular, the invention provides an optimal burst duration assignment methodology such that resources are efficiently utilized and maximized in a communication system such as a code division multiple access (CDMA) system. According to the invention, burst duration is assigned based on channel fading fluctuation and user mobility in the communication system. In general, shorter burst duration is assigned to users with higher fading fluctuation and high mobility. Longer burst duration is assigned to users with lower fading fluctuation and low mobility. In a particular embodiment of the invention, the burst assignment is based on a function of duration versus fluctuation.

Abstract: A method and apparatus to estimate the channel fade (both the amplitude gain/loss and the phase rotation) to assist the receiver to detect and recover the transmitted signal employs a continuous pilot signal such as the pilot code channel or pilot symbols. The channel estimator uses the same scrambling pattern of pilot channel and coherently integrates the continuous pilot signal to yield a channel estimate. The present invention employs adaptive integration duration to yield a channel estimate. The integration duration of the pilot signal for channel estimation is adaptive and proportional to the Doppler period. The Doppler period is proportional to the inverse of Doppler frequency and is an indicator of how fast the channel changes.

Abstract: In a wireless communication system, unique methods are presented to dynamically assign channel codes of different lengths in a manner to maintain orthogonality among assigned channels. In one embodiment, channel codes that require relatively long-lengths are assigned from a first end of a list of unassigned channel codes and channel codes of a shorter length are assigned from an opposing end of a list of unassigned channel codes. Assignment of a shorter length code sequence is made if the longer-length channel codes that depend from the proposed shorter length code sequence are available. In another embodiment, the availability of short length channel codes is derived directly from the availability of the longest length channel codes. In this embodiment, a group of longest-length channel codes that contain a common shorter-length code of the desired length are checked for availability. If all the codes of the group are available then the common shorter-length code may be assigned to transmission.

Abstract: A method that adjusts the power level of a set of forward-link signals of a base station responsive to the loading of the forward link as determined by a power level measurement of the signal set. One power level measurement is a pilot fraction of the forward link. Other power level measurements, such as the signal set's power level, can be used, alone or in combination, instead of or in addition to the pilot fraction of the forward link to adjust the power level of the signal set. The power level of the signal set can be changed in any manner, including by scaling it by a scaling factor, or by increasing the power level by a fixed or a variable amount. The power level measurement of the signal set is obtained during a current time period. The scaling factor that will be used in the subsequent time period is determined using the power level measurement. In one embodiment of the invention, the scaling factor can be obtained from a look-up table that is based on the power level measurement.

Abstract: The invention provides a power control methodology that increases the performance and the throughput of wireless communication systems. In particular, the invention provides a reverse jamming prevention process that efficiently utilizes power resources in a communication system such as CDMA. The invention advantageously prevents reverse jamming due to link imbalance that results from differences in forward and reverse link coverage. According to the invention, an evaluation set (e-set), which is a super set of the active set of base transceiver stations serving specific users, is determined to prevent the negative effects of reverse jamming. Excessive interference problems in the reverse link, particularly in high-speed wireless systems, are thus avoided.

Abstract: According to an embodiment of the invention, the information is transmitted in symbols encoded at a source to a destination. A log likelihood ratio is respectively calculated for each of the encoded symbols. The calculated log likelihood ratios for the information bits are accumulated where the contribution from each of the encoded symbols is accounted for in the accumulating step. Each of the information bits is decoded according to the accumulated log likelihood ratios. An acknowledgment (ACK) is sent to the source for each block of the decoded information bits that passed the error check. A negative acknowledgment (NACK) is sent to the source for each block of the decoded information bits that did not pass the error check. After the source receives the negative acknowledgment (NACK), the encoded symbols are retransmitted to the destination.

Abstract: Inter-frequency handoffs in a CDMA or other wireless communication system are controlled using a noise-limited coverage trigger metric which is able to distinguish between same-frequency cell boundaries and other-frequency cell boundaries in the system. The trigger metric may be generated as a function of an average signal-to-noise measure for pilot signals received at a mobile station of the system and a linear sum of the signal-to-noise measures. The signal-to-noise measures may be generated in the mobile station and included in messages transmitted from the mobile station to one or more base stations of the system. The trigger metric is used to control a handoff from a current frequency to a new frequency in an ongoing call. The trigger metric may alternatively be based on a measure of mobile receive power alone.

Abstract: In order to effectively terminate a burst transmission in a wireless system, a method and apparatus determines whether or not a burst transmission from a wireless unit to a base station should be terminated by evaluating at least one criterion related to the operation of the wireless system. Once it is determined that a burst transmission should be terminated, the transmission is terminated by lowering a target signal-to-noise ratio (SIR) by a predetermined amount. By lowering this target SIR, power control bits transmitted from the base station to the wireless unit instruct an extreme decrease in power of the burst transmission and quickly act to terminate the burst transmission.

Abstract: The invention provides a novel methodology for increasing the performance of CDMA systems with packet data services by accommodating a variety of users with different rates. The invention operates to increase the spectrum efficiency of a wireless system by using an optimal transmission set of base transceiver stations and assigning proper data rates to efficiently utilize the radio resources. In particular, the invention operates to decrease interference so that the quality of data transmission in CDMA systems is advantageously maintained. Moreover, the invention operates to increase the allocation of bandwidth, particularly for high-speed data services. The invention provides a methodology to evaluate the data rates of different combinations of BTSs that may be in connection with a particular mobile station (MS), allocate an appropriate data rate for the MS and make allocation of system resources more efficient in a multi-user environment.

Abstract: An apparatus for performance improvement of a digital wireless receiver, having a plurality of signals, has a processing circuit and a weight generation circuit. The processing circuit provides a processed signal, wherein a plurality of weights is applied to a plurality of signals producing a plurality of weighted signals and the plurality of weighted signals are combined to provide the processed signal. In the weight generation circuit the plurality of weights are generated as a function of a conjugate of channel estimate of a corresponding signal of the plurality of signals and a variance of the corresponding signal. A method implementing the present invention is also described.

Abstract: A mobile communications system employs extended channel assignment messaging during the call setup portion of a mobile call. As part of the call setup process, a mobile station sends an access request message to a primary base station that includes a list of alternate base stations. As call setup continues, the mobile station employs diversity reception in monitoring the paging channel of three base stations, each selected as a function of the strength of the signal-to-noise ratios of their respective pilot tones.

Abstract: The present invention is a method for efficiently utilizing spectrum resources belonging to a wireless communications system in the presence of data channels through a discontinuous data transmission technique. The discontinuous data transmission technique involves the transmission of a flag over a control channel (or some other communication channel) in frame f, wherein the flag would indicate to an intended recipient that a transmitter has a data frame to transmit to the recipient in some future frame f+q. In an embodiment, the transmitter would subsequently transmit the data frame over a data channel (or some other communication channel) in frame f+q if the flag indicated that the data frame was ready to be transmitted. In another embodiment, the transmitter would not transmit the data frame unless the recipient has indicated (via another flag) that the recipient is ready to receive the frame of data from the transmitter.

Abstract: Methods and systems are provided to control transmit power in a wireless transmitter. By receiving a number of transmit control protocol (TCP) segments, converting the TCP segments to radio link control (RLC) frames and transmitting the RLC frames based on a predetermined targeted frame error rate, the initial RLC frames are transmitted using a minimum of power. Any unsuccessfully transmitted RLC frames are cyclically re-transmitted, along with a number of new RLC frames, at decreasing targeted frame error rates, until all RLC frames in a given transmission cycle are successfully transmitted. Accordingly, a new block of RLC frames are transmitted at the predetermined maximum targeted frame error rate. By transmitting RLC frames in this fashion, the overall transmit power can be reduced as compared to conventional transmission techniques, while increasing total data throughput.

Abstract: A method and system for controlling down link transmit power during a soft hand-off in a spread-spectrum wireless system supports independent power control of multiple forward channels to reduce fading. For a soft hand-off, a mobile switching center determines if a forward control channel is transmitted from different sectors of base stations than a forward data channel is. The base stations preferably adjust transmit powers of the forward channels grouped into different physical channels by receiving power control data over the allocated reverse power control channels to compensate for fading of the forward channels during a soft hand-off.