Methods, systems, and devices for wireless communications are described. A device (e.g., a base station or a user equipment (UE)) may identify a sequence length corresponding to a number of resource blocks, and select a modulation scheme based on the sequence length. The device may select, from a set of sequences associated with the modulation scheme, a sequence having the sequence length. In some examples, the set of sequences may include at least one of a set of time domain phase shift keying computer-generated sequences or a set of frequency domain phase shift keying computer-generated sequences. The device may generate a reference signal for a data transmission based on the sequence and transmit the reference signal within the number of resource blocks.

Aspects of the present application provide methods and devices for using a combined QAM and APSK modulation scheme in a hybrid modulation form in order to benefit from advantages of each respective modulation scheme. The proposed hybrid modulation scheme is less sensitive to phase noise and has lower PAPR than QAM and has very similar performance as QAM with respect to AWGN.

Embodiments herein disclose a method and system for designing a waveform for data communication. The method includes applying, by a phase rotation applying unit, a constellation specific phase rotation between consecutive data symbols in a data stream to obtain a constellation rotated data stream. Further, the method includes introducing, by a frequency domain pulse shaping filter, an inter symbol interference (ISI) between modulated data symbols of the constellation rotated data stream, such that the ISI develops the waveform of the constellated rotated data stream to be transmitted.

Embodiments herein disclose a method and system for designing a waveform for data communication. The method includes applying, by a phase rotation applying unit, a constellation specific phase rotation between consecutive data symbols in a data stream to obtain a constellation rotated data stream. Further, the method includes introducing, by a frequency domain pulse shaping filter, an inter symbol interference (ISI) between modulated data symbols of the constellation rotated data stream, such that the ISI develops the waveform of the constellated rotated data stream to be transmitted.

A method and system for cross-technology communication from a WiFi device to a ZigBee device includes: generating, by a WiFi transmitter, to-be-transmitted symbol-level energy modulation bits information simultaneously carrying WiFi data bits and cross-technology data bits transmitted to the ZigBee device, wherein the cross-technology data bits are obtained based on symbol-level energy modulation; and a ZigBee receiver processing received signal strength indication sample information and initiating a cross-technology communication receiving process to obtain the cross-technology data bits needing to be received, and meanwhile a WiFi receiver obtaining the to-be-transmitted symbol-level energy modulation bits information through a standard WiFi receiving process, and then initiating a WiFi data recovery process to obtain original WiFi data bits.

This application provides a data transmission method and apparatus. The method includes: A terminal device determines an actual transmit power for first uplink data based on a determined channel transmit power and a transmission parameter. The actual transmit power is less than or equal to the channel transmit power, and the transmission parameter includes one or more of parameters that can be used to indicate a location of the terminal device. The terminal device sends the first uplink data at the actual transmit power. Therefore, the terminal device may determine the actual transmit power for the uplink data based on the channel transmit power and various transmission parameters that can indicate whether the terminal device is located at a cell edge, so that the actual transmit power for the uplink data can be flexibly adjusted, thereby improving data transmission reliability.

An elevator system (2) comprises an elevator car (4a-d) that is moveable within a hoistway (6a-d). The elevator car (4a-d) comprises a first wireless communication unit (12a-d). A controller (8a-d) is arranged to communicate with the elevator car (4a-d) , the controller (8a-d) comprising a second wireless communication unit (14a-d). The first and second wireless communication units (12a-d, 14a-d) are arranged to exchange elevator operational data using a wireless communication protocol. Each data symbol within a set of data symbols corresponding to the elevator operational data is modulated onto a plurality of orthogonal sub-carriers using an orthogonal frequency division multiplexing modulation scheme. The modulated plurality of orthogonal sub-carriers are transmitted between the first and second wireless communication units (12a-d, 14a-d) over a wireless interface (16a-d).

The present specification provides a method by which a terminal transmits an uplink signal in a wireless communication system. Particularly, the terminal scrambles a plurality of bits for transmission of an uplink signal, and generates a plurality of complex symbols by modulating the plurality of bits according to a specific modulation method. In addition, the terminal repetitively performs, a predetermined number of times, discrete Fourier transform (DFT) and inverse fast Fourier transform (IFFT) on at least one complex symbol of the plurality of complex symbols, and transmits the uplink signal, which is generated through the DFT and IFFT, to a base station, wherein the at least one complex symbol has a phase value which is increased or reduced as much as a specific value according to a symbol index.

Methods, systems, and devices for wireless communications are described. A device (e.g., a base station or a user equipment (UE)) may identify a sequence length corresponding to a number of resource blocks, and select a modulation scheme based on the sequence length. The device may select, from a set of sequences associated with the modulation scheme, a sequence having the sequence length. In some examples, the set of sequences may include at least one of a set of time domain phase shift keying computer-generated sequences or a set of frequency domain phase shift keying computer-generated sequences. The device may generate a reference signal for a data transmission based on the sequence and transmit the reference signal within the number of resource blocks.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may generate a Reed Muller generating matrix for an information bit vector that includes a plurality of information bits. The wireless communication device may remove, from the Reed Muller generating matrix, a row vector consisting of all 1-values to form a modified Reed Muller generating matrix. The wireless communication device may encode the information bit vector using the modified Reed Muller generating matrix to form a codeword. The wireless communication device may transmit the codeword without transmitting a pilot signal or demodulation reference signal for the codeword. Numerous other aspects are provided.