A transmitting method includes: configuring a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating time resources and frequency resources to a plurality of transmission data; and transmitting the frame, wherein the frame includes a first period in which a preamble which includes information on a frame configuration of the frame is transmitted, and a second period in which the plurality of transmission data are transmitted by at least one of time division and frequency division, and among the plurality of OFDM symbols, OFDM symbols included in the second period include pilot symbols arranged along a time axis with a predetermined spacing therebetween, and a predetermined number of data symbols.

Provided are a frame configuring unit configured to configure a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating time resources and frequency resources to a plurality of transmission data, and a transmitter which transmits the frame. The frame includes a first period in which a preamble which includes information on a frame configuration of the frame is transmitted, a second period in which a plurality of transmission data are transmitted by time division, a third period in which a plurality of transmission data are transmitted by frequency division, and a fourth period in which a plurality of transmission data are transmitted by time division and frequency division.

A radio receiver for processing digital chirp spread-spectrum modulated signals that comprise a plurality of frequency chirps that are cyclically time-shifted replicas of a base chirp profile, said time-shifts being an encoded representation of a transmitted message. Includes a soft demapping unit that is adapted for working on fully populated as well as on partial modulation sets, and implements a timing error correction loop that acts back both in the time domain and in the frequency domain.

A transmitting method includes: configuring a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating time resources and frequency resources to a plurality of transmission data; and transmitting the frame, wherein the frame includes a first period in which a preamble which includes information on a frame configuration of the frame is transmitted, and a second period in which the plurality of transmission data are transmitted by at least one of time division and frequency division, and among the plurality of OFDM symbols, OFDM symbols included in the second period include pilot symbols arranged along a time axis with a predetermined spacing therebetween, and a predetermined number of data symbols.

Provided are a frame configuring unit configured to configure a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating time resources and frequency resources to a plurality of transmission data, and a transmitter which transmits the frame. The frame includes a first period in which a preamble which includes information on a frame configuration of the frame is transmitted, a second period in which a plurality of transmission data are transmitted by time division, a third period in which a plurality of transmission data are transmitted by frequency division, and a fourth period in which a plurality of transmission data are transmitted by time division and frequency division.

In 60 GHz WiGig/IEEE 802.11ad, Orthogonal Frequency Division Multiplexing (OFDM) is used to achieve higher throughput. However, OFDM has one problem of high Peak-to-Average Power Ratio (PAPR) caused by the summing up of the large number of subcarriers. A high PAPR signal degrades the efficiency of power amplifier (PA) and may cause spurious emissions because of the PA non linearity. In order to reduce PAPR, Generalized Frequency Division Multiplexing (GFDM) which has the characteristics of both single carrier and multi carrier transmission has been studied. By introducing GFDM, the number of subcarriers can be decreased while still maintaining a high throughput.

This disclosure provides systems, methods and apparatus, including computer storage media, for sidelink communications using partial symbols to reduce overhead of automatic gain control (AGC) and gaps. A transmitting user equipment (UE) maps a sidelink signal to a subset of resource elements in a frequency domain allocation defined via a comb for a first orthogonal frequency division multiplexing (OFDM) symbol. The transmitting UE performs an inverse discrete Fourier transform (IDFT) on the resource elements to generate a first time domain signal that includes a number of repetitions of a first waveform based on a structure of the comb. The transmitting UE transmits at least one repetition of the first waveform of the first time domain signal during at least a portion of the first OFDM symbol. A receiving UE performs AGC and a discrete Fourier transform on portions of the time domain signal.

A method for receiving a wireless signal, performed by a first communication node, may comprise: storing a wireless signal received by the first communication node as samples in a buffer; performing partial correlation operations on the stored samples by a plurality of partial correlators; performing a first FFT operation on results of the partial correlation operations; performing a cumulative product operation on results of the first FFT operation; performing a second FFT operation based on a result of the cumulative product operation; and performing synchronization estimation based on the results of the first FFT operation and a result of the second FFT operation.

A method for receiving a wireless signal, performed by a first communication node, may comprise: storing a wireless signal received by the first communication node as samples in a buffer; performing partial correlation operations on the stored samples by a plurality of partial correlators; performing a first FFT operation on results of the partial correlation operations; performing a cumulative product operation on results of the first FFT operation; performing a second FFT operation based on a result of the cumulative product operation; and performing synchronization estimation based on the results of the first FFT operation and a result of the second FFT operation.

A transmitting method includes: configuring a frame using a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, by allocating time resources and frequency resources to a plurality of transmission data; and transmitting the frame, wherein the frame includes a first period in which a preamble which includes information on a frame configuration of the frame is transmitted, and a second period in which the plurality of transmission data are transmitted by at least one of time division and frequency division, and among the plurality of OFDM symbols, OFDM symbols included in the second period include pilot symbols arranged along a time axis with a predetermined spacing therebetween, and a predetermined number of data symbols.