Roland Sperlich

7778345, Aug 17, 2010

Nov 7, 2007

11/936551

Roland Sperlich - Dallas TX, US
Gregory C. Copeland - Plano TX, US

Texas Instruments Incorporated - Dallas TX

H04B 15/00
H04B 1/10
H04L 25/49

375285, 375296, 375346

In one embodiment of the invention, a modulator mixes a transmit-path signal based on a local oscillator (LO) signal and an amplifier amplifies the mixed transmit-path signal to generate an output signal for transmission. A demodulator generates a receive-path signal based on the output signal and the LO signal. Phase-shift control components provide the output signal and the LO signal to the demodulator during a first time duration and provide a phase-shifted version of one of the output signal and the LO signal to the demodulator during a second time duration. The demodulator generates a second receive-path signal based on the one of the phase-shifted output signal and the phase-shifted LO signal during the second time duration. At least one predistortion circuit adjusts at least one of the transmit-path signal and the receive-path signal based on a difference in signal characteristics of the receive-path signal during the second time duration relative to the first time duration.

7783263, Aug 24, 2010

Dec 14, 2006

11/610563

Roland Sperlich - Dallas TX, US
Gregory C. Copeland - Plano TX, US

Texas Instruments Incorporated - Dallas TX

H04B 7/005
H04J 3/00

455 73, 370278, 370280

A transceiver for time-domain duplexed (TDD) communications, for example in connection with wireless broadband data communications, is disclosed. The transceiver includes digital predistortion compensation circuitry, which compensates the digital signals to be transmitted based on feedback signals from the output of the power amplifier, in order to linearize the output from the power amplifier. The feedback signals from the power amplifier are coupled back to the digital predistortion circuitry over part of the same receive path as the received signals from the wireless communications channel. The shared path includes analog-to-digital converters that are used both in the transmit period of the TDD cycle to convert the feedback signals from the power amplifier output, and in the receive period of the TDD cycle to convert the analog received signals.

7814450, Oct 12, 2010

Dec 29, 2007

11/967079

Roland Sperlich - Dallas TX, US
Amer Hani Atrash - Dallas TX, US

Texas Instruments Incorporated - Dallas TX

G06F 17/50

716 6, 716 1, 716 4, 716 5

Systems and methods for transmitting a signal having a desired phase at the device are disclosed. The systems and methods further include determining a signal path length to a device over a transmission line and adding a delay to a signal to be transmitted over the transmission line. The determination is made in response to determining the path length to the device.

8306149, Nov 6, 2012

Oct 1, 2009

12/571435

Fernando Alberto Mujica - Allen TX, US
Hardik Prakash Gandhi - Mountain View CA, US
Lei Ding - Plano TX, US
Milind Borkar - Dallas TX, US
Zigang Yang - Plano TX, US
Roland Sperlich - Dallas TX, US
Lars Morten Jorgensen - Royal Oaks CA, US
William L. Abbott - Portola Valley CA, US

Texas Instruments Incorporated - Dallas TX

H04L 25/03
H04L 25/49

375296, 375297, 4551143, 708316

An apparatus is provided. In the apparatus, an input to index (I2I) module maps a complex input into a real signal. A real data tap delay line is coupled to the I2I module and includes N delay-elements. A complex data tap delay line is configured to receive the complex input and includes M delay elements. A set of K of non-linear function modules is also provided. Each non-linear function module from the set has at least one real input, at least one complex input, and at least one complex output. A configurable connectivity crossbar multiplexer couples K of the N real tap delay line elements to real inputs of the set non-linear functions and couples K of the M complex tap delay line elements to complex inputs of the set non-linear function modules.

8306150, Nov 6, 2012

Jun 25, 2010

12/823714

Fernando A. Mujica - Allen TX, US
Carson A. Wick - Atlanta GA, US
Lei Ding - Plano TX, US
Milind Borkar - Dallas TX, US
Roland Sperlich - Dallas TX, US

Texas Instruments Incorporated - Dallas TX

H04K 1/02
H04L 25/03
H04L 25/49

375296, 375297, 375285, 375231, 375232, 4551142, 4551143

Systems and methods for identifying a transmission channel response and a feedback channel response from a plurality of composite system responses are disclosed. A plurality of shifted feedback signals are created by shifting a feedback signal frequency by a plurality of first offset values and/or by shifting a transmission signal frequency by a plurality of second offset values. The feedback signals are compared to an input signal to identify the transmission channel response and/or a feedback channel response. A control signal is generated for a pre-distortion circuit to modify the input signal by an inverse of the transmission channel response. The composite system response is measured at a plurality of operating frequencies and at the plurality of offset values. The measurements are stored in a matrix and singular value decomposition is applied to the matrix of measurements to calculate the transmission channel response and feedback channel response.

8311083, Nov 13, 2012

Dec 29, 2009

12/648898

Lei Ding - Dallas TX, US
Zigang Yang - Plano TX, US
Fernando Mujica - Allen TX, US
Roland Sperlich - Dallas TX, US

Texas Instruments Incorporated - Dallas TX

H04L 5/16

375219, 375260, 375296, 375340, 455 631, 455 6713, 4551142, 455126

Conventional transceivers do provide some compensation for in-phase/quadrature (I/Q) imbalance. However, these techniques do not separately compensate for I/Q imbalance for the transmitter and receiver sides of the transceiver. Here, a transceiver is provided that allows for compensation of I/Q imbalance in the transmitter and receiver irrespective of the other to allow for a more accurate transceiver.

20080111622, May 15, 2008

Nov 14, 2007

11/940096

Roland Sperlich - Dallas TX, US
Gregory Clark Copeland - Plano TX, US
Russell Hoppenstein - Richardson TX, US

H03F 3/68

330124 R

One embodiment of the invention includes an amplifier system. The system comprises a digital predistortion (DPD) system configured to receive an input signal and to provide the input signal as a first digital signal component along a first amplifier path and a second digital signal component along a second amplifier path. The system also comprises a first digital-to-analog converter (DAC) configured to convert the first digital signal component to a first analog signal component and a second DAC configured to convert the second digital signal component to a second analog signal component. The system further comprises a Doherty amplifier comprising a main amplifier in the first amplifier path that is configured to amplify the first analog signal component and a peak amplifier in the second amplifier path that is configured to amplify the second analog signal component.

20080130789, Jun 5, 2008

Dec 12, 2006

11/638300

Gregory Clark Copeland - Plano TX, US
Roland Sperlich - Dallas TX, US

H04L 25/03

375297

System and methods for a digital linearization of a non linear element. Digital predistortion methods and circuitry for linearizing a non-linear element that address long or “memory” effects and shorter duration effects, these two predistortion functions are operated together in an adaptive fashion with the non-linear element to provide a highly linear system. A short duration predistortion block comprises an Nth order polynomial filter coupled to a programmable linear equalizer. The Nth order filter includes programmable non-linearities and variable delay taps. The Nth order filter may be configured to implement a non-sequential or a sequential ordered polynomial. The equalizer may, in a preferred embodiment, include circuitry for equalizing imbalances between real and complex signal values. The Nth order filter may implement a compound Volterra filter. The combined system of the predistortion circuitry and a non-linear element has a linear input-output signal response. Methods for initializing, parameterizing and adapting the system are disclosed.