Disclosed in the present invention are a method and device for transmitting and detecting a synchronous signal, which is used to solve the problem that there is currently no clear solution as to how should a terminal detect a synchronous signal when multiple types of base-band numerology are defined in a new wireless communication system. The method comprises: a terminal determining a base-band numerology used to detect a synchronous signal; the terminal detecting the synchronous signal according to the determined base-band numerology. The terminal first determines a base-band numerology used to detect a synchronous signal before detecting said synchronous signal, and then detects the synchronous signal according to the determined base-band numerology, so as to identify the base-band numerology used in the synchronous signal transmission in future communication systems which support multiple types of base-band numerology, thereby correctly detecting the synchronous signal.

Systems and methods for canceling carrier frequency offset (CFO) and sampling frequency offset (SFO) in a radio receive chain are disclosed. In one embodiment, a method is disclosed, comprising: receiving a sub-frame via a radio receive chain in a time domain; performing per-user filtering on the sub-frame to obtain a signal for a particular user; obtaining a CFO correction signal; adding the CFO correction signal in the time domain to perform a CFO correction step on the signal for the particular user; performing an FFT on the output of the CFO correction step to obtain samples in a frequency domain; adding an SFO correction signal in the frequency domain to perform an SFO correction to the output of FFT step; and demodulating the output of SFO correction step, thereby performing CFO and SFO correction while reducing inter-carrier interference (ICI).

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.

A time and frequency synchronization method that includes the steps outlined below is provided. A wireless signal from a base station is received. The wireless signal is delayed on a time domain and is further correlated with the original wireless signal to generate a delayed and correlated signal. Primary symbols related to a primary synchronization signal are delayed and are further correlated with the original primary symbols to generate delayed and correlated primary symbols. The delayed and correlated signal and the delayed and correlated primary symbols are correlated to identify the position of the primary synchronization signal based on a primary peak value. The position of the secondary synchronization signal is identified based on the position of the primary synchronization signal.

A disclosure of the present specification provides a method for receiving a control channel in a search space. The method may comprise the steps of: determining an order of multiple search spaces in a blind decoding; and performing the blind decoding in the multiple search spaces according to the determined order. In this regard, the order of the multiple search spaces may be determined on the basis of delay sensitivity.

The present invention is designed to properly transmit demodulation reference signals for UL data channels in short TTIs. A user terminal according to one aspect of the present invention has a transmission section that transmits a demodulation reference signal for an uplink (UL) data channel, and a control section that controls the transmission of the demodulation reference signal, and, when the UL data channel is transmitted in a second transmission time interval (TTI), which is comprised of a smaller number of symbols than a first TTI, the control section maps the demodulation reference signal to a symbol that is selected based on the arrangement pattern of the second TTI.

A synchronizing radio receiver is disclosed, comprising: an analog baseband receive chain and a digital baseband receive chain. The digital baseband receive chain may comprise an analog to digital converter, a frame synchronization module, a frequency synchronization module, and an orthogonal frequency division multiplexing (OFDM) demodulator, wherein the frequency synchronization module is configured to cross-correlate a plurality of in-phase and quadrature samples to generate a synchronization signal and output the synchronization signal to a local oscillator in the analog baseband receive chain. The digital baseband receive chain may also further comprise a carrier frequency offset (CFO)/sampling frequency offset (SFO) correction module coupled to a frequency synchronization module configured to cross-correlate a plurality of in-phase and quadrature samples, with the CFO/SFO correction module configured to apply correction in a digital domain before outputting a corrected signal to the OFDM demodulator.

Disclosed in the present invention are a method and device for transmitting and detecting a synchronous signal, which is used to solve the problem that there is currently no clear solution as to how should a terminal detect a synchronous signal when multiple types of base-band numerology are defined in a new wireless communication system. The method comprises: a terminal determining a base-band numerology used to detect a synchronous signal; the terminal detecting the synchronous signal according to the determined base-band numerology. The terminal first determines a base-band numerology used to detect a synchronous signal before detecting said synchronous signal, and then detects the synchronous signal according to the determined base-band numerology, so as to identify the base-band numerology used in the synchronous signal transmission in future communication systems which support multiple types of base-band numerology, thereby correctly detecting the synchronous signal.

The present disclosure includes example downlink signal sending methods, downlink signal receiving methods, and devices. In one example method a transmit end device indicates position information of at least one of a first signal or a second signal in time domain based on a position relationship between the first signal and the second signal in at least one of frequency domain or time domain. The transmit end device can then send a frame including the first signal and the second signal. In embodiments of the present invention, position information of a synchronization signal in time domain can be indicated, and sending of a single-symbol synchronization signal is also supported.

Techniques and devices for signaling control and system information are provided. In one aspect, a base station determines a type of multiplexing and a periodicity for transmission of remaining minimum system information (RMSI). The type of multiplexing is for multiplexing the RMSI with a synchronization signal (SS) block. The base station generates an indicator that signals the type of multiplexing and the periodicity. In another aspect, a user equipment (UE) identifies the indicator and determines the type of multiplexing and the periodicity based on the indicator. The UE processes the transmission of RMSI based on the type of multiplexing and the periodicity. Other aspects and features are also claimed and described.