摘要:
A method and apparatus are described that provides flexible spectrum usage by using a paired frequency division duplex (FDD) spectrum to enable dynamic access in television white space (TVWS), sub-leased spectrum or unlicensed spectrum, (e.g., industrial, scientific and medical (ISM) bands), in a femto cell environment or the like. Elastic FDD (E-FDD) enables femto cell operation in TVWS, sub-leased spectrum and/or unlicensed spectrum, either simultaneously with licensed spectrum or as an alternate channel to licensed spectrum. E-FDD enables dynamic asymmetric bandwidth allocation for uplink (UL) and downlink (DL) in FDD, and enables variable duplex spacing, (i.e., using FDD with minimum duplex spacing between DL and UL spectrum, or, using hybrid-FDD, (FDD in a time duplexed fashion), when a spectrum gap between the UL and DL spectrum is below a certain minimum threshold. Additionally, the signaling enhancements to implement E-FDD are also provided.
摘要:
A method and apparatus for a secondary wireless transmit/receive unit (WTRU) to use of secondary cellular spectrum are provided. The secondary WTRU monitors transmissions of a primary WTRU; determines whether to provide assistance to the primary WTRU; and in response to a determination to provide assistance, performs cooperative communications with the primary WTRU for its transmission of data to a base station. If the assistance results in the data being transmitted to the base station faster than it would have with out assistance, the secondary WTRU may utilize uplink resources originally intended for the primary WTRU.
摘要:
An adaptive equalizer including an equalizer filter and a tap coefficients generator used to process a sample data stream derived from a plurality of received signals is disclosed. The tap coefficients generator includes an equalizer tap update unit, a vector norm square estimator, an active taps mask generator, a switch and a pilot amplitude reference unit used to minimize the dynamic range of the equalizer filter. A dynamic mask vector is used to mask active taps generated by the equalizer tap update unit when an unmasked signal output by the equalizer filter is selected by the switch to generate an error signal fed to the equalizer tap update unit. A fixed mask vector is used to mask active taps generated by the equalizer tap update unit when a masked signal output by the equalizer filter is used to generate the error signal.
摘要:
An apparatus for estimating and correcting baseband frequency error in a receiver is disclosed. An equalizer performs equalization on a sample data stream and generates filter tap values based on the equalization. An estimated frequency error signal is generated based on at least one of the filter tap values. A rotating phasor is generated based on the estimated frequency error signal. The rotating phasor signal is multiplied with the sample data stream to correct the frequency of the sample data stream. Alternatively, a channel estimator performs channel estimation and generates Rake receive finger weights based on at least one of the finger weights. An estimated frequency error signal is generated based on at least one of the finger weights.
摘要:
A step-size estimator for controlling the step-size of an adaptive equalizer incorporated in a transceiver (e.g., a wireless transmit/receive unit (WTRU)). The step-size estimator updates at least one adaptive equalizer tap used by the adaptive equalizer based on an apparent speed of a channel established between the transceiver and another transceiver. The step-size estimator includes a speed estimator, a signal-to-noise ratio (SNR) averager and a step-size mapping unit. The speed estimator is used to estimate the apparent speed of the channel (i.e., the observed and/or measured rate of change of the channel impulse response). The SNR averager generates a common pilot channel (CPICH) SNR estimate. The step-size mapping unit uses the speed estimate and the CPICH SNR estimate to generate a step-size parameter, μ, and a filter taps leakage factor parameter, α, used by the adaptive equalizer to update the filter tap coefficient.
摘要:
A wireless transmit receive unit (WTRU) provides facilitation of cell search. In one embodiment, received samples are split into a plurality of sample sets for processing. Each of the sets is processed and an accumulated result is divided by an estimated noise value. In another embodiment, a code correlator correlates the received signal with a primary synchronization code and an auxiliary code correlator having a same length as the code correlator correlates the received signal with a code having a low cross correlation with the primary synchronization code. In another embodiment, a division of an accumulated result with a noise estimate is performed using indexes of the most significant bits.
摘要:
A step-size estimator for controlling the step-size of an adaptive equalizer incorporated in a transceiver, (e.g., a wireless transmit/receive unit (WTRU)). The step-size estimator updates at least one adaptive equalizer tap used by the adaptive equalizer based on an apparent speed of a channel established between the transceiver and another transceiver. The step-size estimator includes a speed estimator, a signal-to-noise ratio (SNR) averager and a step-size mapping unit. The speed estimator is used to estimate the apparent speed of the channel, (i.e., the observed and/or measured rate of change of the channel impulse response). The SNR averager generates a common pilot channel (CPICH) SNR estimate. The step-size mapping unit uses the speed estimate and the CPICH SNR estimate to generate a step-size parameter, μ, and a filter taps leakage factor parameter, α, used by the adaptive equalizer to update the filter tap coefficient.
摘要:
A method and system for determining amplitude and phase compensation values used to adjust the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter. The compensation values may be determined in response to detecting a significant temperature change in the transmitter. Corresponding amplitude and phase adjustment signals having levels that correspond to the compensation values are provided to respective amplitude and phase imbalance compensation modules to adjust the amplitude and phase characteristics of at least one of the real and imaginary signal components.
摘要:
A method and apparatus for dynamically adjusting the impedance between a transmitter's power amplifier (PA) and antenna to efficiently transfer power from the PA to the antenna. The impedance between the PA and the antenna is adjusted based on power level measurements and/or PA direct current (DC) consumption measurements, depending on whether the PA is a linear PA or a switch-mode PA. In another embodiment, a hybrid PA including a first stage linear PA and a second stage switch-mode PA is implemented in a transmitter. The hybrid PA selectively connects the output of the first stage linear PA to one of the input of the second stage switch-mode PA and the output of the hybrid PA, depending on the output power level of the first stage linear PA, the output power level of the hybrid PA, or a requirement indicated by a transmit power control (TPC) command.
摘要:
In order to compensate for performance degradation caused by inferior low-cost analog radio component tolerances of an analog radio, a wireless communication transmitter employs a control process to implement numerous digital signal processing (DSP) techniques to compensate for deficiencies of such analog components so that modern specifications may be relaxed. By monitoring a plurality of parameters associated with the analog radio, such as temperature, bias current or the like, enhanced phase and amplitude compensation, as well as many other radio frequency (RF) parameters may be implemented.