摘要:
In providing a wireless location communication service including a location based service to a user of a mobile device, the mobile device sends information concerning a location of the device relative to a given position in a wireless communication system. The given position may be that of a base station in the system. First information concerning a location of the base station (e.g, GPS information) is communicated to the mobile device, e.g., via broadcast. The mobile device determines second information concerning its location, e.g., based on signals from GPS satellites received thereby. The mobile device then generates relative location information based at least on the first and second information.
摘要:
In providing a wireless location communication service including a location based service to a user of a mobile device, the mobile device sends information concerning a location of the device relative to a given position in a wireless communication system. The given position may be that of a base station in the system. First information concerning a location of the base station (e.g, GPS information) is communicated to the mobile device, e.g., via broadcast. The mobile device determines second information concerning its location, e.g., based on signals from GPS satellites received thereby. The mobile device then generates relative location information based at least on the first and second information.
摘要:
A method and system for predicting a signal power to interference metric for a communication channel in a coverage area of a phase sweep diversity communication system are provided. In the method, a signal power to interference metric for the communication channel is predicted based on a sweep frequency for transmissions in the coverage area. The signal power to interference metric predicted may be a carrier-to-interference ratio or a signal-to-noise plus interference ratio.
摘要:
A method of handoff utilizing a combined signal quality measurement to trigger or initiate a handoff of a mobile station to a plurality of neighbor base stations, wherein the combined signal quality measurement corresponds to a summation of signal quality measurements associated with the plurality of neighbor base stations. The handoff is triggered when the combined signal quality measurement is greater than a handoff threshold. By using the combined signal quality measurement instead of a signal quality measurement of an individual neighbor base station, handoffs can be triggered earlier along a boundary shared by neighbor cells, thereby reducing interference associated with later triggered handoffs. When triggered, the mobile station is handed off to a plurality of neighbor base stations allowing the mobile station to establish simultaneous communication links with two or more neighbor base station. This increases the chance that at least one of the communication links or the combination thereof is a strong communication link, thereby improving the reliability and success rate of handoffs.
摘要:
A system is implemented on a wireless network for adjusting a forward link power control parameter based on forward link feedback. A wireless unit is in communication with several base stations during soft handoff, and provides feedback relating to forward link quality, e.g., forward link pilot signal strength or traffic channel frame error rate. The feedback is compared to a comparison or reference point (such as target frame error rate, or a maximum pilot signal strength in the active set) chosen for gauging the quality or nature of the feedback for power control purposes. Based on this comparison, a power control parameter of one or more of the base stations may be adjusted upwards or downward. The power control parameter may be a forward link reference transmit power level “Pref” used to control base station power transmission levels in the presence of power control bit errors.
摘要:
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. In one embodiment, a mobile station reports to a serving base station only after the former determines that the received power level of a control signal from the base station is less than a threshold level initially provided to the mobile station by the base station. The procedure is applicable, e.g., to base station cells of a first CDMA cellular system which cells border on cells of an analog (AMPS) or a second CDMA cellular system.
摘要:
A base station in a soft handoff adjusts its transmit power level by a first amount if the base station is participating in a soft handoff and by a second amount if the base station is not participating in the soft handoff, i.e. in simplex mode. The first and second amounts are different. In one embodiment of the invention, the adjustment is performed by using a down-step size that is larger in magnitude than an up-step size when the base station is in soft handoff. The transmit power level is then adjusted by the smaller up and larger down step sizes when the base station receives an indication to adjust the transmit power level. The step sizes used when the base station is in simplex mode is larger than the up-step size and smaller than the down step size. In another embodiment, when the base station is in soft handoff, the adjustment is performed by adjusting the transmit power level by the same step size as used during simplex mode when the base station receives an indication to adjust the transmit power level and then reducing the result by a reduction amount. The order of these two steps can be reversed, and the transmit power level can be first reduced by the reduction amount and then adjusted by the same step sizes as used during simplex mode. The reduction amount has a magnitude greater than zero and smaller than the step size. The method of adjusting the base station transmit power level by different amounts based on whether the base station participating in a soft handoff can be used with the method of programming each base station in a soft handoff with a threshold power level to constrain the power transmitted by the base station on the forward link. When the threshold power level is a minimum-threshold power level, each base station maintains its transmit power level at or above the minimum-threshold power level. When the threshold power level is a maximum-threshold power level, each base station maintains its transmit power level at or below the maximum-threshold power level. The threshold power level can be either an adjustable or a fixed threshold power level.
摘要:
A method is disclosed for determining when a request for a higher transmission rate should be granted to a mobile station that currently has access to a communication system to facilitate the maintenance of a performance target (quality of service level) of the reverse link. The method for determining when a mobile station can have access to a higher transmission rate includes obtaining first and second estimated performance indicators for a reverse link of the base station that a mobile station is currently accessing. A blocking threshold value is established. Access at the requested higher transmission rate is based on a comparison of the first and second indicators relative to the established blocking threshold value. If access is denied at the requested higher rate, access will be granted at the next lower rate which will not degrade the performance of the wireless communication system.
摘要:
A method for reducing multiple dominant pilots in a CDMA transmission system comprises linking a transceiver element with a nearby base station for transporting signals between the transceiver element and the nearby base station. Transmitting from the transceiver element forward link signals of a nearby sector associated with the nearby base station. An apparatus is also described.
摘要:
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.