A method of recovering information encoded by a modulated sinusoidal waveform having first, second, third and fourth data notches at respective phase angles, where a power of the modulated sinusoidal waveform is reduced relative to a power of an unmodulated sinusoidal waveform within selected ones of the first, second, third and fourth data notches so as to encode input digital data. The method includes receiving the modulated sinusoidal waveform and generating digital values representing the modulated sinusoidal waveform. A digital representation of the unmodulated sinusoidal waveform is subtracted from the digital values in order to generate a received digital data sequence, which includes digital data notch values representative of the amplitude of the modulated sinusoidal waveform within the first, second, third and fourth data notches. The input digital data is then estimated based upon the digital data notch values.

An optical network includes a transmitter portion configured to (i) precode an input digitized stream of symbols into a precoded symbol stream, (ii) pulse shape the precoded symbol stream with an eigenvalue channel matrix, and (iii) transmit the pulse shaped symbol stream over a digital optical link. The optical network further includes a receiver portion configured to (i) recover the pulse shaped symbol stream from the digital optical link, (ii) decompose eigenvalues of the eigenvalue channel matrix from the recovered symbol stream, and (iii) decode the decomposed symbol stream into an output symbol stream.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme achieving multiple access by multiplexing multiple signals at the transmitter-side performs allocation of transmission resources to a first signal and a second signal, combining and converting to a transmission format via OTFS modulation and transmitting the signal over a communication channel. At the receiver, multiplexed signals are recovered using orthogonality property of the basis functions used for the multiplexing at the transmitter.

A semiconductor integrated circuit includes a first circuit configured to carry out digital-to-analog conversion on input data; a high-pass filter configured to reduce a component, the component having a frequency lower than a predetermined cutoff frequency, in delayed input data obtained by delaying the input data, and output the delayed input data; a second circuit configured to carryout the digital-to-analog conversion on the delayed input data that passes through the high-pass filter; and a third circuit configured to drive a transmission signal, the transmission signal based on an addition signal obtained by adding an output signal of the first circuit and an output signal of the second circuit.

Some embodiments include a system and method for enabling communicating Ultra Wideband (UWB) devices to collaborate by exchanging pulse shape information. The UWB devices use the pulse shape information to improve ranging accuracy. The improved ranging accuracy can be used in complex multipath environments where advanced estimation schemes are used to extract an arriving path for time-of-flight estimation. To determine the pulse shape information to be shared, some embodiments include determining location information of a UWB device and selecting the pulse shape information that satisfies regional aspects. The pulse shape information includes a time-zero index specific to a ranging signal that is used by UWB receivers to establish timestamps time-of-flight calculations. Some embodiments include measuring performance characteristics and selecting different pulse shape information based on the performance characteristics for improved accuracy.

Ultra-Wideband (UWB) technology exploits modulated coded impulses over a wide frequency spectrum with very low power over a short distance for digital data transmission. Today's leading edge modulated sinusoidal wave wireless communication standards and systems achieve power efficiencies of 50 nJ/bit employing narrowband signaling schemes and traditional RF transceiver architectures. However, such designs severely limit the achievable energy efficiency, especially at lower data rates such as below 1 Mbps. Further, it is important that peak power consumption is supportable by common battery or energy harvesting technologies and long term power consumption neither leads to limited battery lifetimes or an inability for alternate energy sources to sustain them. Accordingly, it would be beneficial for next generation applications to exploit inventive transceiver structures and communication schemes in order to achieve the sub nJ per bit energy efficiencies required by next generation applications.

A method and apparatus for processing a signal to generate equalizer codes, which are used to control equalization of the signal, that comprises processing the signal to identify the eyes of the signal, and for each eye, calculating an eye height and calculating a noise value. For each eye, squaring the eye height to generate an eye height product and dividing the eye height product by the noise value to generate a Q.sup.2 value. Using the calculated Q.sup.2 values optimizing, through adaptation, the equalizer codes. Calculating the noise values may include calculating an ISI value for each band of the signal and then calculating the eye height for each eye as the difference between the adjacent upper average value and the adjacent lower average value. Then, for each eye, calculating a noise value by summing the ISI value for the band above the eye and the band below the eye.

A system and method of DFT-S-OFDM modulation is provided that uses a set of frequency domain patterns. For a given transmitter, for a set of DFT-S-OFDM symbols, the frequency domain pattern changes according to a time domain hopping pattern. Advantageously, the time domain hopping patterns are defined to allow only a certain amount of overlap, for example for only one DFT-S-OFDM symbol, between any two time domain hopping patterns. This functions to reduce the effect of a collision, when two transmitters use the same frequency pattern, they will do so only for part of the overall transmission. Optionally, frequency domain spectral spreading is used in the transmitter. This can further reduce the PAPR. In the receiver, successive interference cancellation may be employed to reduce the effect of colliding transmissions.

Techniques for peak-to-average power ratio (PAPR) reduction are described. Wireless devices may provide signaling with respect to one or more PAPR shaping resources. For example, a wireless device may provide signaling of PAPR shaping capability information. PAPR shaping capability information may include information regarding one or more PAPR shaping resources the wireless device has a capability to implement. Additionally or alternatively, a wireless device may provide signaling of PAPR shaping information. PAPR shaping information may include information regarding shaping the signal by a wireless device prior to transmission in a communication link by implementing one or more PAPR shaping resources. Other aspects and features are also claimed and described.

Techniques for peak-to-average power ratio (PAPR) reduction are described. Wireless devices may use one or more PAPR shaping resources, such as expanded bandwidth and/or pulse-shaping filtering, for shaping a signal to reduce PAPR. For example, expanded bandwidth may be utilized for adding a cyclic affix (CA), such as may comprise a cyclic prefix (CP), cyclic suffix (CS), etc., and combinations thereof, to a frequency domain data signal to provide a CP augmented frequency domain data signal used to generate a reduced PAPR time domain data signal. Additionally or alternatively, pulse-shaping filtering may be applied to a frequency domain signal to provide a pulse-shaped frequency domain data signal used to generate a reduced PAPR time domain data signal. Other aspects and features are also claimed and described.