A method, an apparatus, a system, and a computer program product for radio synchronous status messaging between communications units in wireless communications systems. A change of status event by one or more first communications devices is detected. A message indicative of the detected change of status event is generated. The generated message is transmitted to one or more second communications devices.

The invention discloses a data processing method and an intelligent terminal based on an orthogonal frequency division multiplexing (OFDM) system. The method comprises: a communication base station inserting equally spaced frequency domain reference signals to frequency domain data; obtaining frequency domain signals by equivalently transforming the frequency domain data being inserted with the frequency domain reference signals, wherein the frequency domain signals comprise the frequency domain reference signals superimposed with the frequency domain data; obtaining time domain signals by performing inverse Fast Fourier Transform (IFFT) on the frequency domain signals, wherein the time domain signals comprise time domain reference signals superimposed with the time domain data; and transmitting the time domain signals to the intelligent terminal.

A method for detecting a constant envelope burst-mode radio frequency (RF) signal with a known periodic synchronization sequence (PSS) represented therein, e.g. to be for reading of data from utility meters. An incoming RF signal is transformed into a digital baseband signal (DBS), and the phase domain part is processed by: 1) applying a correlation algorithm to correlate the DBS with a synchronization pattern corresponding to the PSS. 2) filtering the resulting correlation signal for removing at least a DC component of the correlation signal. 3) down-sampling the filtered correlation signal (or the correlation signal) with a sampling time controlled by a clock aligned with amplitude peaks in the filtered correlation signal (or the correlation signal). 4) performing a decision algorithm on the down-sampled signal to determine if PSS is present in the incoming RF signal. Then, 5) generating an output signal indicating if the known PSS is present in the incoming RF signal, in response to a result of the decision algorithm. The steps 1)-5) serve to detect if an amplitude in the correlation signal indicates the presence of the known PSS. Preferably, a second decision algorithm serves to detect if periodicity in the correlation signal indicates the presence of the known PSS, and finally the results of the first and second decision algorithms can be combined, e.g. by a logic AND operation, to arrive at a sensitive and reliable PSS detection result.

Various embodiments disclosed herein provide for a reciprocity based channel state information acquisition scheme for frequency division duplex wireless communications systems. By converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced since the multi-path of radio propagation is reciprocal in terms of each ray and each cluster of antenna elements. Since the surrounding objects create the same multipath fading for both uplink and downlink transmissions, modeling the channel state information in the Delay-Doppler domain, and adjusting the sign of the Doppler value (negative/positive) can account for the multipath characteristics in both uplink and downlink.

Techniques are described for carrier frequency offset (CFO) and channel estimation of orthogonal frequency division multiplexing (OFDM) transmissions over multiple-input multiple-output (MIMO) frequency-selective fading channels. A wireless transmitter forms blocks of symbols by inserting training symbols within two or more blocks of information-bearing symbols. The transmitter applies a hopping code to each of the blocks of symbols to insert a null subcarrier at a different position within each of the blocks of symbols, and a modulator outputs a wireless signal in accordance with the blocks of symbols. A receiver receives the wireless signal and estimates the CFO, and outputs a stream of estimated symbols based on the estimated CFO.

A control information sending/receiving method and device are provided, to implement indicating a time-frequency location of a control channel to a terminal device in a 5G NR system or a future evolved LTE system. The method includes: receiving, by a terminal device, broadcast information; determining, from at least two predefined time-domain locations, a time-domain location of a broadcast channel carrying the broadcast information; determining a time-domain location of a control channel based on the time-domain location of the broadcast channel; and performing control channel detection in the determined time-domain location of the control channel.

A method of performing adaptive mode switching in a transmitter of a dual mode simultaneous wireless information and power transmission (SWIPT) system, incudes receiving received power of a receiver in a channel; comparing the received power with a predetermined threshold value; selecting one of a single tone mode or a multi-tone mode as a single/multi-tone mode based on the comparison result; selecting a modulation index based on the selected single/multi-tone mode and the received power; and transmitting the selected single/multi-tone mode, the selected modulation index, and a duty cycle to the receiver. The duty cycle is determined based on at least one of power consumed for decoding a single tone signal, power consumed for decoding a multi-tone signal, and power harvested during the channel by the receiver.

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.

A control information sending/receiving method and device are provided, to implement indicating a time-frequency location of a control channel to a terminal device in a 5G NR system or a future evolved LTE system. The method includes: receiving, by a terminal device, broadcast information; determining, from at least two predefined time-domain locations, a time-domain location of a broadcast channel carrying the broadcast information; determining a time-domain location of a control channel based on the time-domain location of the broadcast channel; and performing control channel detection in the determined time-domain location of the control channel.

A radio receiver comprises a matched filter bank and a decision unit. The matched filter bank has a plurality of filter modules for generating correlation-strength data from a sampled radio signal, each filter module being configured to cross-correlate the sampled signal with data representing a respective filter sequence. The decision unit is configured to use the correlation-strength data to generate a sequence of decoded symbols from the sampled signal. The matched filter bank and/or decision unit are configured to determine the value of each symbol in the sequence in part based on the value of a respective earlier decoded symbol from the sequence of decoded symbols.