A method of signal communication is disclosed comprising providing source data having a predetermined signal power; mapping the source data onto a first modulation scheme to obtain a first set of complex symbols; mapping the source data onto at least one further modulation scheme to obtain at least one further set of complex symbols; combining the first set of complex symbols and the at least one further set of complex signals to form a modulated signal to be forwarded along a communications channel. Beneficially, the predetermined signal power of the source data is split between the first modulation scheme and the at least one further modulation scheme.

A demodulation method and apparatus is disclosed that is for use on a modulated communication signal. The method includes receiving the modulated signal including a first set of complex symbols and at least one further set of complex symbols; applying a Forward Error Correction (FEC) decoding technique; applying a first phase estimation technique to the first set of symbols; applying a second phase estimation technique to the further set of symbols to determine phase information for the modulation signal using a first phase estimation means; and repeating in part using at least one further phase estimation means to identify the presence of phase rotation. Beneficially the method enables the use of large block sizes in the FEC technique.

The present specification relates to a method for transmitting, by a terminal, a demodulation reference signal (DMRS) in a wireless communication system supporting narrow-band (NB)-Internet of things (IOT), the method comprising: generating, for single tone transmission, a reference signal sequence to be used for demodulation; mapping the reference signal sequence to a plurality of symbols; and transmitting, in the plurality of symbols, the demodulation reference signal to a base station by using a single tone, wherein phase rotation is applied to each of the plurality of symbols.

Methods, systems, and devices for multiple access with interference mitigation are described. A wireless communication method is provided to comprise: generating, from information bits, a modulated signal; spreading the modulated signal using a spreading code to provide a spread data signal; processing the spread data signal through a randomization; and transmitting an orthogonal frequency division multiplexing (OFDM) signal based on an output of the processing.

Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for an input sequence of coefficients, an output sequence and generating a waveform using the output sequence. The output sequence corresponds to an output of a convolutional modulation between a three-coefficient function associated with

[00001]$\frac{\sqrt{2}}{2},$

1, and

[00002]$\frac{\sqrt{2}}{2}$

and an intermediate sequence. The intermediate sequence is generated by inserting zero coefficients between coefficients of the input sequence of coefficients

Artificial Intelligence (AI) means are disclosed for enabling network operators to optimize 5G and 6G messaging performance, in real-time. AI models, or fieldable algorithms derived therefrom, can select an appropriate modulation scheme according to network conditions. Modulation variables can then be adjusted to optimize performance, such as throughput or failure rates, for low or high traffic densities. Three development phases are described: network data acquisition including faults experienced under various network conditions, AI structure tuning for accurate prediction of performance, and implementation of a fieldable algorithm based on the AI structure. Network operators can use the fieldable algorithm to compare predicted performance metrics in real-time, according to various operating conditions (such as available modulation schemes), and thereby adjust particular modulation parameters (such as amplitude or phase levels).

A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i×Δλ to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. Δλ satisfies π/2 radians<Δλ<π radians or π radians<Δλ<3π/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i×Δλ to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. Δλ satisfies π/2 radians<Δλ<π radians or π radians<Δλ<3π/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

A method making modifications during a key phase of physical layer security methods and enabling the physical layer security methods to be applicable in a wireless communication is provided. The method includes a step of generating a K common key, including steps to be carried out at a modulator during a data transmission phase.

In mobile communications networks, requirements on signal distortion may be fulfilled at a lower bit rate, or alternatively quantization noise be reduced for a given bit rate, by including fractional exponent bits in a block floating point format. One or more fractional exponent bits may apply to all samples in the block. Alternatively, fractional bits may apply to sub-blocks within the block. The optimal number of fractional bits depends on the number of samples in the block.