Methods, systems, and devices for wireless communications are described. A non-coherent modulation configuration may be selected for a transmission of a set of data based on a radio frequency spectrum band used for the transmission. After selecting the non-coherent modulation configuration, the set of data may be modulated using a differential phase shift keying modulation technique. After selecting the non-coherent modulation configuration, a set of frequency-domain symbols may be generated from the set of modulated symbols using a discrete Fourier transform. The set of frequency-domain symbols may be mapped to a set of subcarriers, and a time-domain waveform may be generated from the mapped set of frequency-domain symbols, yielding a time-domain waveform. The time-domain waveform may be transmitted over the radio frequency band.

The present invention relates to a satellite communications system comprising a satellite with a spatial digital modulator for transmitting an incoming bit stream in multiple beams, wherein the spatial digital modulator configured to generate transmit symbols by dividing the incoming bit stream into symbols of a symbol alphabet and to allocate each transmit symbol to a specific beam. The invention further relates to a method for transmitting a bit stream by such a satellite communications system.

Binary data is processed through a differential pre-encoder, which includes a simple modulo-2 addition. This step is used to cancel the propagation error that can be introduced by duo-binary modulation and to simplify demodulation. Next the duo-binary encoder introduces controlled Inter Symbol Interference between a previously sent bit and a present bit to compress the spectral density closer to the DC. Next a 60-GHz carrier is modulated and transmitted over differential transmission lines.

Disclosed is a method for sensitivity control in a near-field communication, NFC, device operating in a receiving mode. The method comprises calculating a threshold value, using a threshold value calculating unit, as a function of a determined current received signal strength indicator, RSSI, value, optionally a determined current gain control, GC, value, and further optionally a so-called margin value that is a product-specific parameter, and applying the calculated threshold value as a threshold parameter to a threshold comparison unit, which is configured to receive, as input. a first time-derivative signal derived from a combined output signal that is determined as a function of a digital I-channel signal output and a digital Q-channel signal output of an I&Q demodulating block, to compare the first time-derivative signal with the applied threshold parameter, and to provide a binary output that is indicative of whether the input first time-derivative signal is greater than the applied threshold parameter or not.

Methods, systems, and devices for contention-based transmissions using differential coding techniques in mobile communication technology are described. An exemplary method for wireless communication includes transmitting, by a wireless device, a payload that comprises an identity of the wireless device and at least one of a user plane data or a control plane data, where the payload is modulated using a differential coding technique. Another exemplary method for wireless communication includes receiving, by a network node, a payload that comprises an identity of the wireless device and at least one of a user plane data or a control plane data, where the payload is modulated using a differential coding technique.

Methods, systems, and devices for contention-based transmissions using differential coding techniques in mobile communication technology are described. An exemplary method for wireless communication includes transmitting, by a wireless device, a payload including a first portion that is modulated using a differential coding technique and a second portion that is modulated using an amplitude-shift keying (ASK) or phase-shift keying (PSK) modulation, and where the payload includes an identity of the wireless device and at least one of a user plane data or a control plane data.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a mobile station may obtain a multi-level coding (MLC) configuration to be applied to a quadrature amplitude modulation (QAM) constellation set comprising a plurality of constellation symbols and having a non-linearity that is based at least in part on a phase noise or a power amplification associated with the plurality of constellation symbols. The mobile station may process the QAM constellation set, using MLC set partitioning in accordance with the MLC configuration, based at least in part on the phase noise or the power amplification associated with the plurality of constellation symbols of the QAM constellation set. Numerous other aspects are described.

Optimal GMSK training sequences are generated by applying a base sequence to the in-phase component of the even samples and rotating the base sequence by 2.sup.k-1 and applying the second sequence to the quadrature component of the odd samples. Using the optimal GMSK training sequence a channel estimate can be generated. Filtering the channel estimate converts the channel impulse response to one that can be used with a non-GMSK signal e.g. PSK or QAM.

Methods and systems are described for obtaining a set of carrier-modulated symbols of a carrier-modulated codeword, each carrier-modulated symbol received via a respective wire of a plurality of wires of a multi-wire bus, applying each carrier-modulated symbol of the set of carrier-modulated symbols to a corresponding transistor of a set of transistors, the set of transistors further connected to a pair of output nodes according to a sub-channel vector of a plurality of mutually orthogonal sub-channel vectors, recovering a demodulation signal from the carrier-modulated symbols, and generating a demodulated sub-channel data output as a differential voltage on the pair of output nodes based on a linear combination of the set of carrier-modulated symbols by controlling conductivity of the set of transistors according to the demodulation signal.

Advanced modulation and demodulation schemes for LoRa or equivalent chirp spread spectrum transmissions, with differential modulation and symbol repetition improve the sensitivity in combination with soft demodulation methods.