Abstract:
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.
Abstract translation: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。
Abstract:
Methods and apparatuses for data aided channel quality estimation using both pilot and data information are disclosed herein. In one exemplary aspect, a method for estimating channel quality in a wireless communication system is disclosed. The method comprises estimating a pilot noise variance based on a pilot signal received from a base station on a downlink and estimating a data noise variance based on a data signal received from the base station on the downlink. The method also comprises combining the pilot noise variance and the data noise variance to obtain a combined noise variance, and estimating the channel quality based on the combined noise variance.
Abstract:
Techniques for performing equalization at a receiver are described. In an aspect, equalization is performed by sub-sampling an over-sampled input signal to obtain multiple sub-sampled signals. An over-sampled channel impulse response estimate is derived and sub-sampled to obtain multiple sub-sampled channel impulse response estimates. At least one set of equalizer coefficients is derived based on at least one sub-sampled channel impulse response estimate. At least one sub-sampled signal is filtered with the at least one set of equalizer coefficients to obtain at least one output signal. One sub-sampled signal (e.g., with largest energy) may be selected and equalized based on a set of equalizer coefficients derived from an associated sub-sampled channel impulse response estimate. Alternatively, the multiple sub-sampled signals may be equalized based on multiple sets of equalizer coefficients, which may be derived separately or jointly. The equalizer coefficients may be derived in the time domain or frequency domain.
Abstract:
To perform erasure detection for an intermittently active transport channel with unknown format, a receiver determines an energy metric and a symbol error rate (SER) for a received block with CRC failure. The receiver computes uncorrelated random variables u and v for the received block based on the energy metric and SER, the estimated means and standard deviations of the energy metric and SER, and a correlation coefficient indicative of the correlation between the energy metric and SER. The receiver then evaluates the uncorrelated random variables u and v based on at least one decision criterion and declares the received block to be an erased block or a DTX block based on the result of the evaluation. The decision criterion may be defined based on a target probability of false alarm and adjusted based on another metric, such as a zero state bit, for the received block.
Abstract:
User experiences on wireless devices are affected by communication, computation, and user interface capabilities. Another key performance indicator of a wireless device is its battery life. A method, algorithm and apparatus for improving the communication, computation and user interface capabilities of a mobile device is disclosed, which requires the expenditure of less energy and increases battery life. The trade-off between battery life and user experience related to the communication capability is managed by a protocol stack power optimization algorithm that optimally allocates energy resources. The power management algorithm inputs and combines measurements made at various layers of the protocol stack to selectively control a set of actions impacting energy usage. The algorithm maps from a set of measurements to a set of actions that provides the best trade-off between user experience and energy consumption.
Abstract:
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.
Abstract:
An apparatus, system, and method efficiently manage transmission power in a user equipment (UE) device by maintaining and applying an authorized power level to determine a transmission power level after a power limited transmission and before a new power control command has been received. The UE device maintains the authorized power level by monitoring and adjusting the authorized power level based on received power control commands. After a power limited transmission where the maximum power level is less than the authorized power level, the UE device determines the transmission power level for the next transmission based on the authorized power level. Accordingly, after the power limiting situation has ceased, the UE device transmits at the optimum power level eliminating the inefficiencies of transmitting at a lower than authorized power before the next power control command is received.
Abstract:
A circuit and algorithm are disclosed for a step2 search of a three step search of synchronization channels in a W-CDMA system. A mobile terminal of the CDMA system includes an RF downconverter for receiving I and Q signals. A searcher, responsive to the I and Q signals, includes a first correlator for correlating the I and Q signals with a primary synchronization code on a primary synchronization channel, and a second correlator for correlating I and Q signals with a secondary synchronization code on a secondary synchronization channel. The correlated I and Q signals are added for each of the secondary synchronization codes. An energy calculator and a maximum energy detector use the correlated I and Q signals of both the primary and secondary synchronization channels to detect the most likely scrambling code group of secondary synchronization codes.
Abstract:
A circuit and algorithm are disclosed for a step2 search of a three step search of synchronization channels in a W-CDMA system. A mobile terminal of the CDMA system includes an RF downconverter for receiving I and Q signals. A searcher, responsive to the I and Q signals, includes a first correlator for correlating the I and Q signals with a primary synchronization code on a primary synchronization channel, and a second correlator for correlating I and Q signals with a secondary synchronization code on a secondary synchronization channel. The correlated I and Q signals are added for each of the secondary synchronization codes. An energy calculator and a maximum energy detector use the correlated I and Q signals of both the primary and secondary synchronization channels to detect the most likely scrambling code group of secondary synchronization codes.
Abstract:
Techniques for performing equalization at a receiver are described. In an aspect, equalization is performed by sub-sampling an over-sampled input signal to obtain multiple sub-sampled signals. An over-sampled channel impulse response estimate is derived and sub-sampled to obtain multiple sub-sampled channel impulse response estimates. At least one set of equalizer coefficients is derived based on at least one sub-sampled channel impulse response estimate. At least one sub-sampled signal is filtered with the at least one set of equalizer coefficients to obtain at least one output signal. One sub-sampled signal (e.g., with largest energy) may be selected and equalized based on a set of equalizer coefficients derived from an associated sub-sampled channel impulse response estimate. Alternatively, the multiple sub-sampled signals may be equalized based on multiple sets of equalizer coefficients, which may be derived separately or jointly. The equalizer coefficients may be derived in the time domain or frequency domain