Abstract:
A rake receiver finger assignor is configured to assign a rake receiver finger to a time offset between identified signal path time offsets in accordance with a concentration of identified signal paths from a transmitter to a rake receiver. In accordance with the exemplary embodiment, a number of identified signal paths having time offsets within a time window are observed to determine the concentration of signal paths identified by a path searcher. If the number of identified signal paths indicates a concentrated distribution of signal paths such as during a fat path condition, at least one rake finger is assigned between at a time offset between two identified signal paths.
Abstract:
A position determination system and apparatus for utilizing a network of cellular base stations to determine position of a mobile station includes taking a plurality of statistically independent data measurements of the pilot signals from the base stations. Each of the data measurements includes an earliest time of arrival, providing multiple independent measurements for each of the pilot signals. For each cellular base station, a representative measurement is calculated responsive to the independent measurements, which is used to determine position of the mobile station using an AFLT algorithm and/or in conjunction with a GPS algorithm. In some embodiments, the data measurements for each pilot signal further include an RMSE estimate and time of measurement for each time of arrival, and an energy measurement for all resolvable paths. If the mobile station comprises a cell phone, a cell search list and a GPS search list may be provided by a cell base station.
Abstract:
A parameter estimator for estimating one or more parameter(s) from a correlation function derived from a signal using a dynamically variable integration time is described. The parameter estimator may be employed in a subscriber station to estimate the time of arrival of one or more base station or sector pilot signals in a wireless communication system. This information may be utilized in an overall advanced forward link trilateration (AFLT) process for estimating the location of the subscriber station.
Abstract:
A method and apparatus for reducing frequency space from code space search is disclosed in a wireless network. The method and apparatus reduces the frequency space without compromising the probability of detection, so that user equipment can expedite system acquisition and reduce power consumption. To reduce the frequency space, the described aspects note that the power spectral density of the WCDMA signal is essentially flat within the channel bandwidth. By capturing in-phase quadrature samples and doing frequency domain analysis of the signal in bandwidth around the center frequency, to the described aspects can eliminate some channels from the WCDMA code space search during frequency scan.
Abstract:
Methods and apparatus for out of service processing with varied behaviors. In an aspect, a method is provided for service acquisition. The method includes determining one or more conditions, wherein each condition is associated with at least one weight, detecting whether an out-of-service event has occurred, and if an out-of-service event is detected: identifying selected conditions and associated weights, and processing the associated weights to determine service acquisition “on” and “off” times. In an aspect, an apparatus includes condition logic configured to determine one or more conditions, wherein each condition is associated with at least one weight, and processing logic configured to detect whether an out-of-service event has occurred, and if an out-of-service event is detected, to identify selected conditions and associated weights, and process the associated weights to determine service acquisition “on” and “off” times.
Abstract:
Techniques for tracking closely spaced multipath and preventing finger merge without monitoring relative positions between each of a plurality of fingers are disclosed. In one aspect, motion limits are determined for each finger. Time-tracking commands that would move the position of a finger outside its respective motion limits are suppressed. In another aspect, motion limits are updated dynamically, the motion limits of each finger determined in accordance with the motion limits of fingers adjacent to it. Various other aspects are also presented. These aspects have the benefit of preventing finger merge, which allows the allocation of multiple fingers to closely spaced multipath, thus increasing performance and system capacity, and mitigating misallocation of system resources.
Abstract:
For cell measurement, a wireless device categorizes cells whose identities are known to the device into multiple sets. The wireless device may obtain these cells from the system via signaling and/or detect these cells via searches. Different sets of cells may be associated with different levels of importance (e.g., for handoff), require different amounts of processing for measurements, and so on. Each set is associated with a particular measurement rate. Cells deemed to be more important (e.g., for handoff) are measured more frequently. Cells deemed to be less important and/or require more processing for measurements (e.g., cells with unknown timing) are measured less frequently. The wireless device performs searches and makes measurements for the cells in each set at the measurement rate selected for that set.
Abstract:
The disclosure is directed to techniques for performing service signal searches with reduced power consumption when a wireless communication device is operating out of service. The techniques include placing the wireless communication device in a “deep sleep” mode when the wireless communication device is not in service. When operating in the deep sleep mode, the wireless communication device reduces power consumption by not looking for paging signals or searching for service signals. The wireless communication device then may periodically enter a wake-up period during which power consumption is increased to perform signal searches in one or more frequency bands. The wireless communication device returns to the deep sleep mode when the signal searches are unsuccessful.
Abstract:
Techniques for efficiently performing system search to obtain service from a wireless system as quickly as possible are described. A terminal initially looks for service from a first (e.g., W-CDMA) system. The terminal identifies network(s) in the first system from which service was received in the past and performs acquisition on each network to look for service. If service is not found for the first system, then the terminal performs a search for a second (e.g., GSM) system. If service is found on the second system, then the terminal obtains service from the second system and avoids a frequency scan for the first system. Otherwise, the terminal performs a frequency scan for the first system using the search results for the second system. The terminal may obtain a list of RF channels detected for the second system and may omit these RF channels and possibly some other RF channels around these RF channels from the frequency scan.
Abstract:
An access terminal (102) reacquires a system frame number (SFN) when a difference between a continuous counter elapsed time (220) and a calculated elapsed time (222) exceeds a threshold. The continuous counter elapsed time (220) is generated by a continuous counter (122) remaining active during a sleep state of the access terminal (102) and the calculated elapsed time (222) is based on a SFN derived from a counter value generated by a discontinuous counter (124) that is deactivated during the sleep state. In one aspect, the continuous counter (122) may be clocked by a continuous clock (118) during a sleep mode and the discontinuous counter (124) may be clocked by a faster clock (120) that is deactivated during the sleep mode. During reactivation after the sleep mode, the discontinuous counter (120) is set, at the counter set time, to a reset counter value (126) corresponding to an SFN indicated by the continuous counter (122).