Staccato Communications, Inc.

Samsung Electronics Co., Ltd.

Denso Corporation

Intel Corporation

Amazon Technologies, Inc.

Veebeam Corporation

Torbjorn Larsson

Nishant Kumar

Dan Meacham

Murali R Krishnan

Yong-suk Kim

Donald R Green, Jr

Ramon A Khalona

Seung-young Park

Timothy Leo Gallagher

Roberto Aiello

A constellation of many satellites and associated ground stations provide communication service to user terminals. These devices use modulation techniques such as orthogonal frequency division multiplexing (OFDM) to send large quantities of data. For transmission, a power amplifier increases the amplitude of a waveform modulated in this way. The power amplifier operates more efficiently closer to saturation. However, operation at saturation results in nonlinear distortion, producing unwanted signals and increasing bit error rate. A set of techniques are used to reduce the peak to average power ratio (PAPR) of the waveform provided to the power amplifier. A distortionless technique remaps blocks of bits to reduce the resulting PAPR of that block. Additional techniques may also be progressively applied to reduce PAPR while minimizing adverse consequences such as in-band distortion, out of band emissions, increased bit error rate, and so forth. These techniques may include filtering, peak cancellation, and circular clipping.

System for reducing crest factor and peak to average power ratio

An orthogonal frequency division multiplexing (OFDM) signal spectrum shaping device comprises an input interface configured to receive an input signal, a modulation portion coupled to the input interface, configured to modulate the input signal to generate a plurality of uncompensated sub-carriers, and a sub-carrier gain control module configured to selectively apply a plurality of gain factors to the plurality of uncompensated sub-carriers to generate a plurality of compensated sub-carriers that are substantially equal in amplitude.

OFDM signal spectrum shaping device and method for OFDM signal spectrum shaping

A TFI-OFDM transmission system for a UWB communication that includes a data generator generating data having a rate corresponding to a transmission speed mode, a convolutional encoder convolutional-encoding the data into a certain number of data groups, an OFDM modulator outputting OFDM symbols by executing an IFFT the data groups a buffer temporarily storing the OFDM symbols to sequentially transmit the OFDM symbols in a time domain at least two times, and a frequency generator generating certain frequencies to transmit the OFDM symbols in a certain number of frequency bands corresponding to transmission channels.

TFI-OFDM transmission/reception systems for UWB communication and methods thereof for mitigating interference from simultaneously operating piconets

A signal to be transmitted is modified. An ultra wideband (UWB) signal to be transmitted is obtained, the UWB signal having a data carrying sub-band and a non data carrying sub-band. Information in the non data carrying sub-band is modified so that the power associated with the non data carrying sub-band is less than the power prior to the modification. Information in the data carrying sub-band is modified so that the power associated with the data carrying sub-band is greater than the power prior to the modification. The amount by which the data carrying sub-band increases in power is based at least in part on the amount by which the non data carrying sub-band decreases in power. A UWB signal is transmitted having the modified information in the non data carrying sub-band and the modified information in the data carrying sub-band.

Increasing OFDM transmit power via reduction in pilot tone

Detecting a boundary within a transmitted packet is disclosed. A first symbol of the transmitted packet is received in a band. A second symbol of the transmitted packet is received in the band. The first and second symbols are compared. The boundary within the transmitted packet is detected based at least in part on the comparison of the first symbol and the second symbol and the band.

Payload boundary detection during multiband receiver synchronization

Transmitting information is disclosed. Interference mitigation information associated with mitigating interference with a victim wireless device is obtained. The interference mitigation information is transmitted.

Communication of interference mitigation related information between wireless devices

A method of improving frequency diversity of a signal that includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols comprises receiving an input data sequence, mapping the input data sequence to a transmission data sequence, wherein the mapping includes performing a mapping operation and generating an OFDM symbol using the transmission data sequence. An orthogonal frequency division multiplexing (OFDM) transmitter comprises an interface configured to receive an input data sequence, and a processor configured to perform a mapping operation, to map the input data sequence to a transmission data sequence wherein the mapping includes performing the mapping operation, and to generate an OFDM symbol using the transmission data sequence.

MB-OFDM transmitter and receiver and signal processing method thereof

Multiband OFDM system with mapping

A method of shaping an orthogonal frequency division multiplexing (OFDM) signal spectrum of a transmitted signal is disclosed. An input signal including an input component is received and a first instance of the input component is generated. The method also includes determining that a second instance of the input component is to be different than the first instance. The second instance of the input component that is different from the first instance is generated. An output signal to be transmitted is generated and includes the first instance and the second instance of the input component.

Spectral shaping for multiband OFDM transmitters with time spreading

A method of shaping an orthogonal frequency division multiplexing (OFDM) signal spectrum is disclosed. The method comprises receiving an input signal that has a frequency spectrum that includes a frequency peak, and limiting the amplitude of the frequency peak to a predetermined clip level. An orthogonal frequency division multiplexing (OFDM) transmitter is disclosed. The OFDM transmitter comprises an input interface configured to receive an input signal that includes a frequency spectrum that includes a frequency peak, and a processor coupled to the input interface, configured to limit the amplitude of the frequency peak to a predetermined clip level.

Spectral shaping in multiband OFDM transmitter with clipping

The power control system includes a run-length counter and a processor. The counter is configured to receive and count power up commands indicating commands to increase power, and to generate a run-length count. The processor provides a transmit power level based on comparison of previous power levels and the run-length count with specified thresholds. The system has a capability to generate transmit power level based on short-term statistics of the previous transmit power levels.

Transmit power reduction mode for CDMA mobile stations

Transmitting an ultra wideband (UWB) signal in some embodiments comprises reducing power within a first sub-band with respect to a nominal power of the UWB signal within the first sub-band and correspondingly increasing power within a second sub-band with respect to a nominal power of the UWB signal within the second sub-band. An ultra wideband (UWB) transmitter comprises an input interface configured to receive data, a modulator configured to modulate received data into symbols and a power shaping component coupled to the modulator, configured to shape power density spectrum of a UWB signal being transmitted. Transmitting an ultra wideband (UWB) signal in some embodiments comprises determining whether to power shape the UWB signal; in the event that it is determined that the UWB signal is to be power shaped, reducing power within a first sub-band with respect to the nominal power of the UWB signal within the first sub-band; and correspondingly increasing power within a second sub-band with respect to the nominal power of the UWB signal within the second sub-band such that bandwidth of the UWB signal is maintained to be greater than or equal to a required bandwidth.

A wireless transmitter includes a data rate controller operating to predictively determine a traffic channel data rate for a frame of data stream using a previous data rate, transmitted bit energy of a traffic channel, and a target data throughput. The data rate controller includes a selector, a bit energy computer, a predictor, an estimator, and a comparator.

Predictive data rate control in wireless transmitters

A system for operating a cellular phone using Bluetooth with a car kit is described. The Bluetooth protocol is used to communicate between the cellular phone and the car kit. A communication can be established between the cellular phone and the said car kit. In one mode, the car kit can be made to assume the identity of the cellular phone and transmit as if it were the cellular phone itself. In another mode, the car kit can become a hands-free set for the cellular phone which communicates with the cellular phone via Bluetooth.

Growing community of inventors

San Diego, CA, United States of America

Torbjorn Larsson