Paragon Communications Ltd.

Lucent Technologies Inc.

Technion Research & Development Foundation Limited

At&t Bell Laboratories

Agere Systems Guardian Corp.

Israel Bar-David

Jack Harriman Winters

Alexander Veinblat

Glenn David Golden

Avner Elia

Nelson Ray Sollenberger

Richard Dennis Gitlin

Carlo Luschi

Thomas L Marzetta

Chih-Lin I

Ran-Hong Yan

Ender Ayanoglu

Ilya Blayvas

Rajeev Krishnamoorthy

A partial envelope tracking (PET) circuitry for improving the dynamic range of a plurality of power amplifiers amplifying radio frequency signals in a MIMO based handheld wireless computing device. The circuitry includes a plurality of sub-PET circuits respectively connected to the plurality of power amplifiers; and a common charging circuit connected to each of the sub-PET circuits and a power source, wherein the common charging circuit comprises a storage capacitor and a logic configured to control the charging of the storage capacitor respective of an operation mode of each of the sub-PET circuits, wherein the operation mode is any one of: a tracking mode and normal mode, wherein during the normal mode of all of the sub-PET circuits the storage capacitor is charged at the voltage level provided by the power source and during the tracking mode of at least one of the sub-PET circuits the storage capacitor is discharged.

Method and apparatus for multiple-output partial envelope tracking in handheld wireless computing devices

A partial envelope tracking (PET) circuit for improving the dynamic range and the efficiency of a power amplifier amplifying high bandwidth signals is provided. The PET circuit includes a main supply path having a main valve (MV) connecting the power amplifier to a first power source; a storage capacitor connecting a junction node and the power amplifier; a supplementary supply path including a DV and a TV, each of the DV and the tracking valve connecting, in parallel between a second power source and the junction node; a supplementary current path including a GV connecting the junction node and a ground; and a valves control unit (VCU) configured to monitor an envelope tracking parameter to determine an operation mode of the circuit and a state of each of the MV, the GV, the DV, and the TV during each respective mode of operation.

Method and apparatus for partial envelope tracking in handheld and wireless computing devices

Circuitry for providing improved pulse-type enhancement of the voltage supplied to a power amplifier () that is fed by a power supply that is connected to the power amplifier () at a feeding point through a main supply path that is connected via an inductor (L). A second feeding point is used for enhancement by a capacitor that is discharged. A transformer L, L, M) is formed by mutually coupling an additional inductor (L), through which an additional supply path is connected. Enhancement power is provided partially through the transformer L, L, M) and the remaining part thorough the capacitor (C). This way, the total level of possible enhancement is increased, while minimizing distortion of the envelope of the amplified RF signal.

Transformer-capacitor enhancement circuitry for power amplifiers

Apparatus for detecting the envelope of an RF signal that comprises an RF transistor operating essentially at a non-linear operating point at the RF frequency range; a DC power supply for feeding the RF transistor; a dummy load for terminating the output of the RF transistor; and at lease one impedance, through which the DC power supply feeds the RF transistor, for obtaining an indication signal developed across the impedance. The indication signal represents the envelope, from the fluctuating current drawn by the RF transistor from the DC power supply during the time period when the RF signal is applied to the feeding input.

Methods and apparatus for detecting the envelope of RF power signals

Method and circuit for stabilizing the output power of a power amplifier, operated with signals having a large peak-to-average ratio and fed by a DC power supply with fluctuating output voltage. An allowable fluctuating range for the voltage output from the DC power supply and a constant voltage level are determined. A controllable voltage enhancement circuitry that can output an enhancement voltage is provided. The input of the voltage enhancement circuitry and a first DC supply path are connected to the output of the DC power supply. The output of the voltage enhancement circuitry is connected to a second DC supply path. While the instantaneous value of the fluctuating output voltage is lower than the constant voltage level, the voltage enhancement circuitry generates an enhancement voltage that causes the sum of the voltages supplied through the first and the second supply paths, to be identical to the constant voltage level.

Method and apparatus for providing a stable power output of power amplifiers, operating under unstable supply voltage conditions

Circuitry for allowing efficient pulse-type enhancement of the voltage supplied to a power amplifier fed by a power supply that is connected to the power amplifier at a first feeding point through a main supply path that is connected via a component having high impedance to an enhancement pulse at the feeding point, and to a second feeding point.

Efficient supply enhancement circuitry for power amplifiers

Method and apparatus for improving the efficiency and the dynamic range of a power amplifier operated with signals having a large peak-to-average ratio. A reference level is determined, above which at least a portion of the magnitude of an input signal being a modulated signal that is input to the power amplifier, or a baseband waveform that is used to generate the modulated signal, is defined as an excess input signal. The magnitude of the input signal is continuously sampled, for detecting an excess input signal. A lower level of operating voltage is supplied to the power amplifier, if no excess input signal is detected. The lower level of operating voltage is sufficient to effectively amplify input signals having a magnitude below the reference level. A higher level of operating voltage is supplied to the power amplifier, whenever an excess input signal is detected. The higher level of operating voltage is sufficient to effectively amplify input signals having a magnitude above the reference level.

Method and apparatus for improving the efficiency of power amplifiers, operating under a large peak-to-average ratio

A method and apparatus for estimating channel impulse response and data in a signal transmitted over a channel in a communication system. The channel impulse response is estimated uses correlative channel sounding, and then, using the estimated channel impulse response, the data in the signal is estimated. The output is then fed back to the channel impulse response estimator and the channel impulse estimation is repeated. The data estimation and channel impulse response estimation may be iterated a number of times.

Iterative channel estimation

An apparatus for performance improvement of a digital wireless receiver comprises a processing circuit for processing a plurality of received signals and providing a processed signal, wherein a plurality of weights is applied to the plurality of received signals producing a plurality of weighted received signals. The plurality of weighted received signals are combined to provide the processed signal. A weight generation circuit generates the plurality of weights wherein weights are based on a given number of interferers.

Subspace method for adaptive array weight tracking

The invention provides methods and apparatus for adaptive adjustment of the phase and amplitude controllers that are needed in Feed Forward Linearized Amplifiers (FFLA) to balance, first, the desired signal component and then the distortion component for the eventual full suppression of the latter. The particular advantage of the methods of the invention is that the adaptive adjustment is achieved without the need for additional RF reference or pilot signals and without RF correlators as proposed in prior art; rather, it is based solely on envelope-detected samples of the signal at two test points and on perturbations of the quiescent operating points of the amplifiers and/or other components, such as vector modulators, by appropriately selected voltage patterns. All these operations are at base band frequencies which makes the apparatus for the adaptive control implementable in simple digital circuitry.

Methods and apparatus for adaptive adjustments of feed-forward

An apparatus for performance improvement of a digital wireless receiver comprises a processing circuit for processing a plurality of received signals and providing a processed signal, wherein a plurality of weights is applied to the plurality of received signals producing a plurality of weighted received signals. The plurality of weighted received signals are combined to provide the processed signal. A weight generation circuit generates the plurality of weights, wherein weights are generated so as to solve a minimization problem that penalizes excessive time variability in the weights.

Time-varying weight estimation

A spread spectrum code pulse position modulated communication system is disclosed. The communication system includes a spread spectrum code pulse position modulated receiver that compensates for the delay spread of a transmission medium, such as a wireless radio channel of a local area network. Delay spread may cause signal components of one transmitted spread spectrum codeword to spill over into chip positions of adjacent symbols, causing intersymbol interference, or into chip positions on quadrature channels of a given symbol interval, such as in a QPSK implementation, causing interchip interference. The disclosed receiver decodes a transmitted spread spectrum code pulse position modulated signal in the presence of such delay spread, utilizing a tentative symbol estimator to sample the matched filter data. The tentative symbol estimator will assign a weight to each potential symbol value, taking into account the cross-rail or bias influence caused by the residual coupling between the signals on quadrature channels for a given symbol duration. In addition, the disclosed receiver includes a mode sifter which evaluates the weighted values for each symbol estimate and assigns final estimates to each symbol value, taking into account the influence of codewords transmitted during one or more successive symbol intervals on one another.

Spread spectrum code pulse position modulated receiver having delay

A spread spectrum code pulse position modulated communication system is disclosed. The frequency spectrum of a transmitted signal is spread by encoding bits with a predefined spectrum-spreading codeword which is in accordance with regulatory requirements or other standardization decisions. When the predefined spread spectrum codeword is passed through a filter matched to the characteristics of the codeword, a peak is detected in the main lobe. A positive main lobe can indicate a binary value of '0' and a negative main lobe, associated with the inverse of the predefined codeword, can represent a binary value of '1'. Additional information is conveyed by modulating the position of the center of the codeword within the symbol duration. In one embodiment, the position of the center of the codeword is varied among eight positions. Thus, eight signal states are available, and three additional bits may thereby be conveyed. Two differently and independently time-shifted spread spectrum codewords may be modulated, each with one of two orthogonal carrier signals, such as a sine and a cosine wave, thereby conveying a total of eight bits per symbol duration. Here, a symbol duration is the duration of a codeword.

Method and apparatus for spread spectrum code pulse position modulation

In a communication system, a network has nodes each connected in a star relationship to a number of end units that include a device for assuming one of an idle, active, or on-line state and for requesting the node to which it is connected to change it from the idle to the active and the active to the on-line state, and for releasing the on-line state on the basis of data at the end unit. The nodes for change the state of an end unit from the idle to the active and from the active to the on-line mode on the basis of available communication time. According to an embodiment of the invention, the nodes change the states to the on line state on the basis of policy preferences for the type of traffic, and specifically to grant priority to stream traffic over batch traffic.

Growing community of inventors

Haifa, Israel

Israel Bar-David