A transmitter transmitting payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols, including: a frame builder configured to receive the payload data and to receive signalling data to use in detecting and recovering the payload data at a receiver, and to form the payload data with the signalling data into frames for transmission: a modulator configured to modulate a first OFDM symbol with the signalling data and to modulate one or more second OFDM symbols with the payload data; a signature sequence processor circuit providing a signature sequence; a combiner circuit combining the signature sequence with the first OFDM symbol; a prefixing circuit prefixing a guard interval to the first OFDM symbol to form a preamble; and a transmission circuit transmitting the preamble and the one or more second OFDM symbols. The guard interval is formed from time domain samples of a part of the signature sequence.

A radio receiver device determines whether a digital radio signal includes a predetermined cyclic preamble. An input portion samples the digital radio signal and generates a plurality of samples for storage in a buffer. A first autocorrelator correlates first and second subsets of the samples to generate a first correlation metric, the second subset having been stored in the buffer earlier than said first subset by an even integer multiple of half of the preamble period. A second autocorrelator correlates first and third subsets of the plurality of samples to generate a second correlation metric, the third subset having been stored in the buffer earlier than said first subset by an odd integer multiple of half of the preamble period. A processing portion calculates a difference between the correlation metrics and determines that the radio signal includes the predetermined cyclic preamble when the difference is greater than a threshold value.

A method is used for frequency offset estimation in a wireless communication network that employs time based scheduling of packets. The method is performed by a packet receiver in the wireless communication network. The method includes receiving a packet from a packet transmitter. The packet includes a preamble that is composed of samples of a single orthogonal frequency-division multiplexing symbol. The preamble has a cyclic prefix (CP) defined by a repetition of samples from an end-portion of the preamble and the preamble, except for the CP, is free from any repeated sequence of samples. The method also includes determining a sequence of similarity measure values between the CP of the preamble and the end-portion of the preamble, applying a low-pass filter to the sequence of similarity measure values, resulting in a filtered sequence of similarity measure values, and performing frequency offset estimation on the filtered sequence of similarity measure values.

Disclosed herein is a method for detecting a covert channel in wireless communication. The method includes setting a wireless communication specification, detecting a covert timing channel, and detecting a covert storage channel.

This disclosure describes systems, methods, and devices related to signal detection. A device may determine a physical layer protocol data unit (PPDU). The device may append a preamble to the PPDU. The device may generate a frame. The device may send the frame.

Half tone offset may be utilized to mitigate signal distortion caused by DC bias within OFDM-based systems. In addition a cyclic prefix may be utilized within an OFDM-based system to mitigate inter-symbol-interference. Presented herein are techniques and methods to efficiently apply a cyclic prefix to an OFDM symbol with a half tone offset.

Examples described herein include systems and methods which include wireless devices and systems with examples of cross correlation including symbols indicative of radio frequency (RF) energy. An electronic device including a statistic calculator may be configured to calculate a statistic including the cross-correlation of the symbols. The electronic device may include a comparator configured to provide a signal indicative of a presence or absence of a wireless communication signal in the particular portion of the wireless spectrum based on a comparison of the statistic with a threshold. A decoder/precoder may be configured to receive the signal indicative of the presence or absence of the wireless communication signal and to decode the symbols responsive to a signal indicative of the presence of the wireless communication signal. Examples of systems and methods described herein may facilitate the processing of data for wireless communications in a power-efficient and time-efficient manner.

An electronic device having a radio is provided. When the radio boots up, the radio may search for downlink signals transmitted by a wireless base station. The device may generate a narrow set of candidate frequencies over which to search for the downlink signals by leveraging a cyclic prefix autocorrelation property of the downlink signals. Each candidate frequency may have a corresponding center frequency offset (CFO) and symbol boundary timing correction that is used when searching over the narrow set of candidate frequencies. To generate the narrow set of candidate frequencies, control circuitry may generate autocorrelated signals from baseband-shifted input signals over a set of different center frequencies and bandwidths. Searching over the narrow set of candidate frequencies may be significantly faster than performing a full raster scan over all frequencies supported by the radio.

A method for transmitting information in a communication system, a base station and a user equipment. The method includes mapping a synchronous signal and a broadcast channel to be transmitted to preset one or more time-frequency resource blocks in a target carrier, where a numerology used by the target carrier is a first numerology group, and the first numerology group includes any one or more numerologies that are allowed to be used by the target carrier; the one or more time-frequency resource blocks are located within an initial access subband of the target carrier and uses a second numerology, where the second numerology is a fixed numerology; the broadcast channel carries at least configuration information of the initial access subband; and the initial access subband is a subband corresponding to a numerology in the first numerology group; and transmitting the one or more time-frequency resource blocks to a user equipment.

The present disclosure relates to a communication technique for fusing, with an IoT technology, a 5G communication system for supporting a higher data transfer rate than a 4G system, and a system therefor. The present disclosure may be applied to intelligent services, such as smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail businesses, security and safety-related services, on the basis of 5G communication technologies and IoT-related technologies. Disclosed is a setting method for an efficient uplink signal transmission of a terminal in a case where a plurality of waveforms are supported to efficiently operate an uplink in a next generation mobile communication.