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: 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: 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: According to one aspect of the invention, a method for determining a power control set point is provided. In one embodiment, the power control set point is determined based on one or more factors including a first factor corresponding to a pilot bit error rate, a second factor corresponding to a normalized signal variance, and a third factor corresponding to an average number of fingers in lock.

Abstract: Techniques for deriving sample timing for multiple signal instances received on multiple antennas for a given propagation path. In one scheme, a DLL is maintained for each path, and each DLL tracks the timing of the best signal instance for the assigned path. In another scheme, a DLL is maintained for each path, and each DLL tracks the average timing of the multiple signal instances for the assigned path. To reduce timing jitter, the SINR of a signal instance may be estimated for a number of different time offsets. The loop filter for the DLL is initially updated in the normal manner. If a change in the time offset used for the sample timing is detected, then the SINRs for the new and prior offsets are compared. The new time offset is used if the associated SINR is better. Otherwise, the prior time offset is retained and used.

Abstract: An apparatus for selecting a best serving sector in a code division multiple access (CDMA) communication system. A comparator compares a plurality of signal levels received from a plurality of active sectors with a signal level of a current serving sector to produce a difference. A delta generator is coupled to the comparator that generates a delta credit for each of the plurality of active sectors based on the difference. An accumulator is coupled to the delta generator and accumulates a plurality of delta credits to produce an accumulated total credit. A best sector identifier that is coupled to the accumulator identifies the best serving sector from the accumulated total credit.

Abstract: Techniques to determine whether or not a terminal is under the coverage of a current wireless communication system (e.g., a packet data system) and to switch from the current system to another wireless communication system (e.g., a voice/data system). In one method, at least one measurement of at least one parameter for at least one base station in the current system is initially obtained. The measurement(s) may be SNR measurements. A metric is derived based on the measurement(s) and used (typically along with a metric threshold and a timer) to determine whether or not the terminal is within the coverage of the current system. A switch to another system is initiated if the terminal is deemed to be outside the coverage of the current system. The two systems provide at least one common service (e.g., packet data service).

Abstract: Devices and methods are provided for providing wireless coverage redundancy in case, for example, the backhaul of an access point (AP) base station is not available. In one embodiment, the method involves monitoring the backhaul, and in response to the backhaul being available, facilitating communication between an access terminal (AT) and the macro network via the backhaul. In addition, or in the alternative (e.g., when the backhaul is not available), a communication signal between the AT and a macro base station (or another AP base station) may be boosted.

Abstract: Techniques to efficiently attempt acquisition of a packet data system (e.g., an IS-856 system). If a terminal has acquired one or more channels in a voice/data system (e.g., an IS-2000 system), then it can attempt acquisition on channels in the packet data system that are co-located with the acquired channels in the voice/data system. Multiple acquisition modes may be used, and on-going acquisition attempts on the co-located channels may be performed using one acquisition mode at a time in order to reduce power consumption. Acquisition attempts may be performed in a “ping-pong” manner to improve the likelihood of acquisition. For a ping-pong search, an acquisition attempt is made on the most recently acquired channel prior to an acquisition attempt on each of the remaining channels. Received signal strength estimates may also be obtained for selected channels and may be used to determine whether or not to attempt acquisition on these channels.

Abstract: Techniques for improving the capacity of a wireless communications system using interference cancellation (IC). In an early decoding and IC aspect, a frame transmitted from a user to a base station may be decoded prior to the entire frame being received by the base station. The remaining portion of the frame may then be re-constructed at the base station prior to its reception, and cancelled from the receive signal to reduce the interference to frames received from other users. In a power control aspect for early decoding and IC, the power control target level at a local base station may be adjusted in response to successfully early decoding a frame, without affecting the overall outer loop power control operation. Further aspects include late decoding techniques for utilizing the IC of other users' signals to improve the probability of decoding a given user's frames, as well as techniques for traffic channel demodulation using channel re-estimation.

Abstract: Systems and methods for performing a handoff of an access terminal from a macro node to a femto node are disclosed. To direct handoff of the access terminal, an identity of the femto node is determined A femto node provided may be indentified by at least a difference between the offset of a first pilot signal and the offset of a second pilot signal.

Abstract: A method of detecting an outage includes determining at a source of data a quality metric of a link over which data is to be transmitted, modifying the quality metric by a quality metric margin, and declaring an outage event when power required for transmission of a reference signal exceeds power required for transmission of the reference signal determined form the modified quality metric. An apparatus for detecting an outage includes means for determining at a source of data a quality metric of a link over which data is to be transmitted, means for modifying the quality metric by a quality metric margin, means for determining a maximum rate of data in accordance with said modified quality metric, and means for declaring an outage event when power required for transmission of data at the maximum rate of data exceeds maximum allowable transmission power.

Abstract: Techniques for improving the capacity of a wireless communications system using interference cancellation (IC). In an early decoding and IC aspect, a frame transmitted from a user to a base station may be decoded prior to the entire frame being received by the base station. The remaining portion of the frame may then be re-constructed at the base station prior to its reception, and cancelled from the receive signal to reduce the interference to frames received from other users. In a power control aspect for early decoding and IC, the power control target level at a local base station may be adjusted in response to successfully early decoding a frame, without affecting the overall outer loop power control operation. Further aspects include late decoding techniques for utilizing the IC of other users' signals to improve the probability of decoding a given user's frames, as well as techniques for traffic channel demodulation using channel re-estimation.

Abstract: The present patent application comprises a method and means for demodulating symbols, comprising converting an OFDM symbol from a time domain to a frequency domain, selecting pilot tones, making a soft decision based on received data, and estimating a channel frequency response. In another example, the method and means further comprises selecting guard tones. In another example, the method and means further comprises generating channel estimates for in-band and band-edge pilot tones.

Abstract: Noise variance estimation in wireless communications. Noise variance estimation includes receiving a signal including an OFDM symbol having, in-band tones including in-band pilot tones, and band-edge tones including band-edge pilot tones and guard tones, estimating an effective noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones, and estimating an effective noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones.

Abstract: A method and an apparatus for quick retransmission of signals in a communication system are disclosed. A transmitting terminal, e.g., a base station, transmits signals in a form of packets to a receiving terminal, e.g., a subscriber station. The receiving terminal determines if the packet was intended for the receiving terminal, and if so, the receiving terminal demodulates the packet. The receiving terminal then computes a quality metric of the packet, and compares the computed quality metric with a quality metric contained in the packet. If the quality metrics match, the packet is declared correctly received, and is forwarded for further processing. If the quality metrics fail to match, the receiving terminal sends a request for retransmission of the packet. The transmitting terminal determines which packet needs to be retransmitted based on the request for retransmission. The transmitting terminal then schedules the packet for retransmission.

Abstract: In one embodiment, the invention comprises a channel estimation method, comprising determining a FFT window position, and calculating a delay spread. In another embodiment, the step of determining a FFT window position comprises setting an initial position of the FFT window, computing an energy for each tap, time averaging said energy for each tap, comparing an average energy of each tap with a first threshold multiplied by the average energy of all taps, comparing the average energy of each tap with a second threshold multiplied by a maximum average energy in alias components, updating the set of paths if the average energy of the tap is greater than said second threshold multiplied by the maximum average energy in alias components; and refining the FFT window position.

Abstract: Methods and apparatus for providing modified timestamps in a communication system. In an aspect, a method includes receiving one or more packets associated with a selected destination, computing an average relative delay associated with each packet, determining a modified timestamp associated with each packet based on the average relative delay associated with each packet, and outputting the one or more packets and their associated modified timestamps. In an aspect, an apparatus is provided for generating modified timestamps. The apparatus includes a packet receiver configured to receive one or more packets associated with a selected destination and processing logic configured to compute an average relative delay associated with each packet, determine a modified timestamp associated with each packet based on the average relative delay associated with each packet, and output the one or more packets and their associated modified timestamps.

Abstract: Wireless communication receiver with hybrid equalizer and RAKE receiver. The receiver compares performance of the system for RAKE only and RAKE in combination with equalizer estimates. The receiver enables or disables the equalizer accordingly.

Abstract: Methods and apparatus used in a wireless communication system. A data request message may be periodically transmitting by a mobile station to a base station. The data request message may provide information about orthogonal codes to be used by the base station to communicate with the mobile station. The mobile station may receive data transmitted by the base station, the data being transmitted by the base station based on the information about the orthogonal codes provided in the data request message. The information about the orthogonal codes may be based on a quality measure made by the mobile station on a forward link pilot channel from the base station to the mobile station.