Methods, systems, and devices for wireless communication are described. A transmitting device may transmit a wakeup message to another device. The wakeup message may be transmitted using a transmit diversity scheme in accordance with aspects of the present disclosure. The transmit diversity may, for example, include a cyclic shift diversity scheme, a phase rotation scheme, a symbol generation scheme, or combinations thereof. The transmit diversity may in some cases improve a communication range of the wakeup message or otherwise benefit the wireless communications system.

This application provides a synchronization signal sending method and receiving method, and an apparatus. In the method, a base station determines a frequency domain position of a target frequency resource based on a frequency interval of synchronization channels, wherein the frequency interval of synchronization channels is 2.sup.m times a predefined frequency resource of a physical resource block, and m is a preset nonnegative integer. The base station sends a synchronization signal by using the target frequency resource.

The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-I and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

The embodiments of the present disclosure disclose an information transmission method, a base station and a terminal. The method comprises: configuring at least one type of subcarrier spacing of synchronization signal and physical broadcast channel and symbol numbers occupied by the synchronization signal and the physical broadcast channel by a base station, wherein, the subcarrier spacing of the synchronization signal is 152.sup.m kHz, the subcarrier spacing of the physical broadcast channel is 152.sup.n kHz, m and n are both integers in a range of 0 to 5; selecting one configuration for sending the synchronization signal and the physical broadcast channel according to a service time delay requirement; determining frequency domain positions and time domain positions of the synchronization signal and the physical broadcast channel, wherein, the frequency domain positions for sending the synchronization signal and the physical broadcast channel are neighboring each other or at least partially overlap, the time domain positions for sending the synchronization signal and the physical broadcast channel are neighboring each other or partially overlap; sending the synchronization signal and the physical broadcast channel to a terminal according to the selected configuration and the determined frequency domain positions and time domain positions. By means of the present disclosure, the time delay of a terminal accessing a communication area can be reduced.

The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

A method and apparatus estimating carrier frequency offset (CFO) with timing synchronization are provided. The apparatus includes processor that receives analog-to-digital converter (ADC) samples, determines a coarse angle from the received ADC samples, obtains an improved coarse angle by altering the coarse angle based on a preamble duration, determines a base CFO estimate from the improved coarse angle and determines a plurality of candidate CFOs based on the base CFO estimate and a difference frequency.

Methods, systems, and devices for wireless communications are described that provide for application of a tone reservation signal for orthogonal time-frequency space (OTFS) waveform communications. A tone reservation signal may use a first subset of resources of a set of resources associated with an OTFS frame, which may mitigate relatively large PAPR associated with transmission of the OTFS frame. A tone reservation signal may use in-frame resources (e.g., as delay-Doppler locations within a delay-Doppler resource grid) of the OTFS frame, or may use tone reservation resources may correspond subcarriers that are out-of-band with subcarriers of an OTFS frame. Signaling may be provided by a transmitting device that indicates the tone reservation resources, and a receiving device may decode a received communication in accordance with remaining resources other than the tone reservation resources.

A method of frequency-offset determination includes: receiving a resource block containing one or more auxiliary frequency-offset estimation signals and pilot signals from a second device; and calculating the one or more auxiliary frequency-offset estimation signals and the pilot signals to determine a frequency offset for demodulating the resource block. At least one of the first device or the second device is a vehicle.

A computer implemented method of providing RSTD data comprising receiving an uncertainty window centered around an expected RSTD value, determining the PDP of each reference OFDM symbol within the uncertainty window, obtaining a main PDP by calculating a parameter indicative of signal quality for each determined PDP, the main PDP having the highest signal quality, obtaining a preceding PDP of the Main PDP, obtaining a succeeding PDP of the Main PDP, determining PDP metrics comprising, determining a channel metric for each of the main, preceding and succeeding PDPs, determining a channel main tap for each of the main, preceding and succeeding PDPs, determining a delay estimate for each of the main, preceding and succeeding PDPs, wherein if the main PDP is a combined PDP, performing coherence testing on the PDP metrics to detect any ambiguity in the delay estimate of the main PDP, and correcting any ambiguity.

The embodiments of the present disclosure disclose an information transmission method, a base station and a terminal. The method comprises: configuring at least one type of subcarrier spacing of synchronization signal and physical broadcast channel and symbol numbers occupied by the synchronization signal and the physical broadcast channel by a base station, wherein, the subcarrier spacing of the synchronization signal is 152.sup.m kHz, the subcarrier spacing of the physical broadcast channel is 152.sup.n kHz, m and n are both integers in a range of 0 to 5; selecting one configuration for sending the synchronization signal and the physical broadcast channel according to a service time delay requirement; determining frequency domain positions and time domain positions of the synchronization signal and the physical broadcast channel, wherein, the frequency domain positions for sending the synchronization signal and the physical broadcast channel are neighboring each other or at least partially overlap, the time domain positions for sending the synchronization signal and the physical broadcast channel are neighboring each other or partially overlap; sending the synchronization signal and the physical broadcast channel to a terminal according to the selected configuration and the determined frequency domain positions and time domain positions. By means of the present disclosure, the time delay of a terminal accessing a communication area can be reduced.