Abstract: The reliability of transmit power control (TPC) commands received from a transmitter is determined based on a TPC target value. The TPC target value is derived based on a TPC threshold and possibly a weight, depending on the receiver implementation. A received TPC command is considered reliable if its absolute value exceeds the TPC target value. Received TPC commands deemed as unreliable are discarded and not used for power control. Multiple TPC target values, used for detecting UP and DOWN commands, may be derived with multiple scaling factors. For a receiver in soft handover and receiving TPC commands from multiple transmitters, a different TPC target value may be derived for each transmitter. The received TPC commands for each transmitter are compared against that transmitter's TPC target value. Received TPC commands deemed as unreliable are discarded and not combined.

Abstract: Systems and techniques are disclosed relating to wireless communications. These systems and techniques involve wireless communications wherein a device may be configured to recover an information signal from a carrier using a reference signal, detect a frequency error in the information signal; and periodically tune the reference signal to reduce the frequency error.

Abstract: In one embodiment, the invention is directed toward frequency tracking techniques using control symbols that include both pilot and non-pilot symbols. For example, both the pilot and non-pilot symbols can be used in estimating frequency error of a received signal. The contribution of non-pilot symbols to the estimation can be weighted according to a confidence level associated with each non-pilot symbol. In some cases, soft decisions are generated for the non-pilot symbols and then used with the pilot symbols for frequency tracking. In this manner, the frequency tracking loop can be improved.

Abstract: A method and apparatus are provided for adjusting a communication receiver based on the velocity of a wireless communication device in relation to a base station. The receiver is adjusted by estimating a frequency shift of a communication signal transmitted between the base station and the wireless communication device (WCD) based on the WCD velocity. Using this estimate, adjustments are made to the communication receiver to account for the frequency shift of the communication signal. Adjustments to the receiver can include adjusting frequency and time tracking loops to account for the change in frequency of a signal received by, and from, the WCD as it moves relative to the base station. The receiver may be located in the WCD, or in the network infrastructure, or in both.

Abstract: A cross product is determined for a received signal. A dot product is also determined for the received signal. If the cross product is greater than a predetermined threshold, the cross product is decremented by the product of the dot product multiplied by a constant value. If the cross product is less than or equal to the predetermined threshold, the cross product is incremented by the product of the dot product multiplied by the constant value. The incrementing or decrementing is continued until the frequency error approaches a minimum value.

Abstract: Techniques for incorporating non-pilot symbols along with pilot symbols to improve the estimate of the characteristics (e.g., amplitude and phase) of a communication link. A pilot filter weighs samples corresponding to pilot and non-pilot symbol by different sets of coefficients, which have values determined by and/or corresponding to the confidence in the detected sample. Samples corresponding to pilot symbols are typically associated with higher degree of confidence and are weighted more (e.g., with weights of 1.0). Samples corresponding to non-pilot symbols are typically associated with lower confidence and are weighted with values that may be variable and dependent on the degree of confidence in the samples (e.g., with weights ranging from 0.0 up to 1.0). The weights are updated based on a particular estimator such as a MAP (Maximum a Posteriori) estimator, a MLE (Maximum Likelihood Estimator), or some other estimator.

Abstract: In one embodiment, the invention is directed toward methods for estimating the power of a received signal encoded with both pilot and non-pilot symbols. The method may include separately accumulating the pilot symbols and the non-pilot symbols and then estimating signal power by calculating a weighted sum of the accumulated pilot and non-pilot symbols. In this manner, a more accurate estimate of the power of the received signal can be obtained.

Abstract: Systems and techniques are disclosed relating to wireless communications. These systems and techniques involve wireless communications wherein a device may be configured to recover an information signal from a carrier using a reference signal, detect a frequency error in the information signal; and periodically tune the reference signal to reduce the frequency error.

Abstract: The reliability of transmit power control (TPC) commands received from a transmitter is determined based on a TPC target value. The TPC target value is derived based on a TPC threshold and possibly a weight, depending on the receiver implementation. A received TPC command is considered reliable if its absolute value exceeds the TPC target value. Received TPC commands deemed as unreliable are discarded and not used for power control. Multiple TPC target values, used for detecting UP and DOWN commands, may be derived with multiple scaling factors. For a receiver in soft handover and receiving TPC commands from multiple transmitters, a different TPC target value may be derived for each transmitter. The received TPC commands for each transmitter are compared against that transmitter's TPC target value. Received TPC commands deemed as unreliable are discarded and not combined.

Abstract: A method and apparatus for using information about a mobile terminal's location relative to a base station can improve performance of a communication system. In addition, information about the mobile terminal's velocity relative to the base station may be used to improve performance of the communication system. The location information may be used to estimate a nominal PN offset, and a set of PN offset to use, for processing communication signals. The velocity information may be used to estimate a nominal frequency of the communication signals.

Abstract: When all of the fingers of a wireless rake receiver are “out-of-lock,” the transmit power is initially maintained at a constant level. When the “out-of-lock” condition persists for an extended period of time, transmit power is increased in an effort to reacquire a lock with a subscriber unit or base station, as the case may be. An increase in transmit power may be effective in reacquiring lock when the cause of the out-of-lock condition is slow fading, rather than fast fading. Slow fading may be evidenced by persistence of the out-of-lock condition for an extended period of time. The length of the out-of-lock condition is used to selectively control transmit power and thereby promote quality of service. Transmit power is only increased when the fingers remain out-of-lock for an extended period of time, thereby avoiding undue increases in transmit power that could produce interference among different subscriber units.

Abstract: A method and apparatus are provided for adjusting a communication receiver based on the velocity of a wireless communication device in relation to a base station. The receiver is adjusted by estimating a frequency shift of a communication signal transmitted between the base station and the wireless communication device (WCD) based on the WCD velocity. Using this estimate, adjustments are made to the communication receiver to account for the frequency shift of the communication signal. Adjustments to the receiver can include adjusting frequency and time tracking loops to account for the change in frequency of a signal received by, and from, the WCD as it moves relative to the base station. The receiver may be located in the WCD, or in the network infrastructure, or in both.

Abstract: A process and apparatus for timing occurs in a timing discriminator that is part of a time tracking loop. The timing discrimination that prevents Rake finger merging. The process for timing discrimination discriminator is coupled to an input signal. The process begins by gathering early, ontime, and late samples of the input signal. Early, Ontime, and Late parameters are then derived in response to the samples. The timing discriminator output is generated in response to a predetermined relationship between the Early, Ontime, and Late parameters. The process and apparatus enables Rake fingers to freely track their paths. This improves the receiver performance.

Abstract: A method is provided for partitioning data into packets, where each packet has a type k selected from a set of packet types, and a length Lk, in bytes, of payload data. The method includes steps of: determining an expected successful transmit time Ek, for packets of type k, for each of the set of packet types; choosing an optimum packet type for which the value Ek/Lk is a minimum; and partitioning the payload data into packets of the optimum packet type. The method is enhanced by computing a bit error rate (BER) from the retransmission rate for single packet type and using the BER to compute retransmission rates for packets of the remaining types. The method is further enhanced by computing transition tables in advance and using the transition tables to select an optimum packet type.

Abstract: A method and apparatus are provided for determining adjustments to be made to a transmitter based on the velocity or location of a wireless communication device in relation to a wireless network infrastructure. The transmitter to be adjusted can be located in either the wireless communication device, or in a device in the wireless communication infrastructure, or both.

Abstract: Techniques to acquire and track a received signal instance (or multipath) based on one or more transmitted pilots. In an aspect, a frequency tracking loop is provided to acquire and track the multipath, and supports a number of loop modes (e.g., acquisition and tracking modes). Each loop mode may be associated with a respective frequency detector and a set of values for a set of elements in the loop. In another aspect, several frequency detectors are provided for deriving estimates of the frequency error in the downconversion of the multipath (e.g., from radio frequency to baseband). In one design, maximum likelihood estimates of the frequency error are derived based on the recovered pilot symbols. In another design, the frequency error estimates for the multipath are derived based on the frequency error estimated for each transmitted signal.

Abstract: When all of the fingers of a wireless rake receiver are “out-of-lock,” the transmit power is initially maintained at a constant level. When the “out-of-lock” condition persists for an extended period of time, transmit power is increased in an effort to reacquire a lock with a subscriber unit or base station, as the case may be. An increase in transmit power may be effective in reacquiring lock when the cause of the out-of-lock condition is slow fading, rather than fast fading. Slow fading may be evidenced by persistence of the out-of-lock condition for an extended period of time. The length of the out-of-lock condition is used to selectively control transmit power and thereby promote quality of service. Transmit power is only increased when the fingers remain out-of-lock for an extended period of time, thereby avoiding undue increases in transmit power that could produce interference among different subscriber units.

Abstract: In one embodiment, the invention is directed toward methods for estimating the power of a received signal encoded with both pilot and non-pilot symbols. The method may include separately accumulating the pilot symbols and the non-pilot symbols and then estimating signal power by calculating a weighted sum of the accumulated pilot and non-pilot symbols. In this manner, a more accurate estimate of the power of the received signal can be obtained.

Abstract: A cross product is determined for a received signal. A dot product is also determined for the received signal. If the cross product is greater than a predetermined threshold, the cross product is decremented by the product of the dot product multiplied by a constant value. If the cross product is greater than or equal to the predetermined threshold, the cross product is incremented by the product of the dot product multiplied by the constant value. The incrementing or decrementing is continued until the frequency error approaches a minimum value.

Abstract: Techniques for incorporating non-pilot symbols along with pilot symbols to improve the estimate of the characteristics (e.g., amplitude and phase) of a communication link. A pilot filter weighs samples corresponding to pilot and non-pilot symbol by different sets of coefficients, which have values determined by and/or corresponding to the confidence in the detected sample. Samples corresponding to pilot symbols are typically associated with higher degree of confidence and are weighted more (e.g., with weights of 1.0). Samples corresponding to non-pilot symbols are typically associated with lower confidence and are weighted with values that may be variable and dependent on the degree of confidence in the samples (e.g., with weights ranging from 0.0 up to 1.0). The weights are updated based on a particular estimator such as a MAP (Maximum a Posteriori) estimator, a MLE (Maximum Likelihood Estimator), or some other estimator.