A receiver-implemented method is for measuring a periodically modulated signal. The method includes applying a received periodically modulated signal to a mixer of a receiver, the periodically modulated signal not synchronized with the receiver, and tuning a local oscillator (LO) of the mixer using an estimate of actual carrier frequency and an estimate of an arbitrary waveform generator (AWG) sampling rate to obtain a digitized intermediate frequency (IF) signal. The method further includes applying a short time Fourier transform (STFT) to the digitized IF signal, extracting a carrier frequency offset and a AWG sampling rate offset based on the applied STFT, compensating for the carrier frequency offset, and applying a digital correction to the STFT to compensate for the AWG sampling rate offset. Compensating for the carrier frequency offset may include retuning the LO to obtain a new digitized IF signal to which the digital correction is applied.

Certain aspects of the present disclosure provide techniques for transmitting and processing reference signals, such as DMRS, that may account for mobility characteristics (e.g., that relate to a Doppler measurement) of a wireless node (e.g., a UE), such as Doppler measurements indicating how fast such a device is moving.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme that maps data symbols, along with optional pilot symbols, using a symplectic-like transformation such as a 2D Fourier transform and optional scrambling operation, into a complex wave aggregate and be backward compatible with legacy OFDM systems, is described. This wave aggregate may be processed for transmission by selecting portions of the aggregate according to various time and frequency intervals. The output from this process can be used to modulate transmitted waveforms according to various time intervals over a plurality of narrow-band subcarriers, often by using mutually orthogonal subcarrier tones or carrier frequencies. The entire wave aggregate may be transmitted over various time intervals. At the receiver, an inverse of this process can be used to both characterize the data channel and to correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme that maps data symbols, along with optional pilot symbols, using a symplectic-like transformation such as a 2D Fourier transform and optional scrambling operation, into a complex wave aggregate and be backward compatible with legacy OFDM systems, is described. This wave aggregate may be processed for transmission by selecting portions of the aggregate according to various time and frequency intervals. The output from this process can be used to modulate transmitted waveforms according to various time intervals over a plurality of narrow-band subcarriers, often by using mutually orthogonal subcarrier tones or carrier frequencies. The entire wave aggregate may be transmitted over various time intervals. At the receiver, an inverse of this process can be used to both characterize the data channel and to correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

A method and apparatus are provided. The method includes, but is not limited to, receiving a universal synchronization signal (USS) including a universal primary synchronization signal (UPSS) and a universal secondary synchronization signal (USSS), wherein the USS is coded using a mother code which is extended to m resource blocks (RBs) and n orthogonal frequency division multiplexing (OFDM) symbols and a code cover of m RBs and n symbols is applied to the mother code, determining a cell identity based on the USS, determining a frame timing based on the USS, and connecting a user equipment to a network using the cell identity and the frame timing.

For example, a wireless communication receiver may be configured to switch one or more RF components of the receiver between an on-state and an off-state based on at least one detection criterion for preamble detection of a frame preamble by a preamble detector of the receiver, switching the one or more RF components between the on-state and the off-state including switching the one or more RF components from the on-state to the off-state based on determination that the at least one detection criterion is not met, and switching the one or more RF components from the off-state to the on-state after an off-state period, wherein a duration of the off-state period is based at least on a preamble duration of the frame preamble; and to repeat switching the one or more RF components between the on-state and the off-state until the frame preamble is detected by the preamble detector.

For example, a wireless communication receiver may be configured to switch one or more RF components of the receiver between an on-state and an off-state based on at least one detection criterion for preamble detection of a frame preamble by a preamble detector of the receiver, switching the one or more RF components between the on-state and the off-state including switching the one or more RF components from the on-state to the off-state based on determination that the at least one detection criterion is not met, and switching the one or more RF components from the off-state to the on-state after an off-state period, wherein a duration of the off-state period is based at least on a preamble duration of the frame preamble; and to repeat switching the one or more RF components between the on-state and the off-state until the frame preamble is detected by the preamble detector.

A wireless telecommunications system that mitigates infrasymbol interference due to Doppler-shift and multipath and enables multiple access in one radio channel. Embodiments of the present invention are particularly advantageous for wireless telecommunications systems that operate in high-mobility environments, including high-speed trains and airplanes.

A wireless telecommunications system that mitigates infrasymbol interference due to Doppler-shift and multipath and enables multiple access in one radio channel. Embodiments of the present invention are particularly advantageous for wireless telecommunications systems that operate in high-mobility environments, including high-speed trains and airplanes.

In a transmitter apparatus, a known reference signal is superimposed on top of a data signal that is typically not known a priori to a receiver and the combined signal is transmitted. At a receiver, an iterative channel estimation and equalization technique is used to recover the reference signal and the unknown data signal. In the initial iteration, the known reference signal is recovered by treating the data signal as noise. Subsequent iterations are used to improve estimation of received reference signal and the unknown data signal.