摘要:
Devices and methods are provided for deploying and/or implementing a low power mode in an access point (AP) base station. The low power mode may be implemented based on the presence and/or status of access terminals (ATs). In one embodiment, the method may involve determining whether any ATs are present within at least one defined coverage area. In another embodiment, the method may involve determining whether the ATs are in an idle or active state.
摘要:
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.
摘要:
Techniques to filter pilot symbols for a pilot in an “adaptive” manner to provide an improved estimate of the response of a communication channel. A received signal may experience different channel conditions at different times, and different multipaths may also experience different channel conditions even when received close in time. A pilot filter with an adaptive response is used to provide an improved estimate of the channel response. Various adaptive pilot filtering schemes may be used. In a first scheme, the channel conditions are estimated based on the quality of the received pilot. In a second scheme, the channel conditions are estimated based on the quality of the pilot estimates (i.e., the filtered pilot symbols). For each scheme, a particular filter response is selected based on the estimated quality of either the received pilot or the pilot estimates.
摘要:
Techniques for filtering noisy estimates to reduce estimation errors are described. A sequence of input values (e.g., for an initial channel impulse response estimate (CIRE)) is filtered with an infinite impulse response (IIR) filter having at least one coefficient to obtain a sequence of output values (e.g., for a filtered CIRE). The coefficient(s) are updated based on the sequence of input values with an adaptive filter, a bank of prediction filters, or a normalized variation technique. To update the coefficient(s) with the adaptive filter, a sequence of predicted values is derived based on the sequence of input values. Prediction errors between the sequence of predicted values and the sequence of input values are determined and filtered to obtain filtered prediction errors. The coefficient(s) of the IIR filter are then updated based on the prediction errors and the filtered prediction errors.
摘要:
Techniques for power control that avoids outer loop wind-up are disclosed. In one aspect, wind-up of a target power level is detected, and the target power level is modified in response. In another aspect, unwinding of the target power level is detected, after which the target power level is determined without considering wind-up. Various other aspects are also presented, including wind-up and unwinding detection procedures, and target power level modification procedures. These aspects have the benefit of reducing the time that transmit power exceeds that which is necessary, thus increasing system capacity and performance, and mitigating misallocation of system resources.
摘要:
Techniques for power control that avoids outer loop wind-up are disclosed. In one aspect, wind-up of a target power level is detected, and the target power level is modified in response. In another aspect, unwinding of the target power level is detected, after which the target power level is determined without considering wind-up. Various other aspects are also presented, including wind-up and unwinding detection procedures, and target power level modification procedures. These aspects have the benefit of reducing the time that transmit power exceeds that which is necessary, thus increasing system capacity and performance, and mitigating misallocation of system resources.
摘要:
Techniques for time tracking diversity pilots are disclosed. In one aspect, an early and a late energy calculation is made on each incoming symbol using a first pilot sequence for despreading. The difference between the two energies is used to drive a tracking loop, which generates a time reference for producing a first pilot estimate and a second pilot estimate, the two estimates used for demodulating data. In another aspect, the early and late energies are made including a plurality of incoming symbols, the number of which corresponds to the number of symbols in a run of positive or negative values in an orthogonalizing sequence. The orthogonalizing sequence is used to generate a second pilot sequence from a first pilot sequence, the resulting second pilot sequence being orthogonal to the first. These aspects have the benefit of simplifying the hardware or processing steps required for transmit diversity time tracking, resulting in cost savings, power savings, simplicity of design, and the like.
摘要:
Erasure detection and power control are performed for an intermittently active transport channel with unknown format. A receiver processes each received block and determines whether it passes or fails CRC. For each received block with CRC failure, the receiver performs erasure detection by computing a symbol error rate (SER) and energy of the received block, comparing the computed SER against an SER threshold, comparing the computed energy against an energy threshold, and declaring an erasure if the computed SER is less than the SER threshold and the computed energy exceeds the energy threshold. The SER and energy thresholds may be adjusted based on the average SER and the average energy for prior received blocks with CRC failures. For power control, an SIR target is increased by an UP step whenever an erased block is detected for the transport channel.
摘要:
Aspects describe infrastructure unassisted inter-device handoff. A method performed by a wireless communications apparatus for inter-device handoff is disclosed. A wireless communications apparatus that performs a network unassisted inter-device handoff is disclosed. A computer program product comprising a computer-readable medium that includes codes for carrying out inter-device handoff is disclosed. At least one processor configured to perform a network unassisted communication handoff is disclosed.
摘要:
Methods and apparatus for active and passive dynamic electromagnetic radiation emission control in wireless devices by limiting transmit power in individual devices is disclosed. In various embodiments, electromagnetic radiation emissions from wireless devices are dynamically controlled using variable transmit power limits acquired through the use of RF ID/NFC tags that indicate transmit power limits, where such power limiting tags are embedded in clothing, furniture, etc., communication of transmit power limits over Bluetooth or other short range technologies, location-based transmit power limits, user input transmit power limits. Controlling the transmit power of mobiles as well as femtocells/access points for the purpose of minimizing SAR using variable transmit power limits is detailed.
摘要翻译:公开了通过限制各个设备中的发射功率的无线设备中的主动和被动动态电磁辐射发射控制的方法和装置。 在各种实施例中,使用通过使用指示发射功率限制的RF ID / NFC标签获得的可变发射功率限制来动态地控制来自无线设备的电磁辐射发射,其中这种功率限制标签嵌入在服装,家具等中,通信 通过蓝牙或其他短距离技术的发射功率限制,基于位置的发射功率限制,用户输入发射功率限制。 详细说明了控制移动台以及毫微微蜂窝/接入点的发射功率,以便使用可变发射功率限制来最小化SAR。