A plurality of multicarrier signals is generated. Each of the plurality of multicarrier signals includes a pilot symbol sequence at a same temporal point in each multicarrier signal. Each pilot symbol sequence includes a plurality of pilot symbols with non-zero amplitude. The pilot symbol sequences are orthogonal to each other at the same temporal point. A quantity of the plurality of pilot symbols in each pilot symbol sequence is greater than or equal to a quantity of the plurality of multicarrier signals to be transmitted. The plurality of multicarrier signals are transmitted in an identical frequency band from a plurality of antennas. The plurality of antennas includes two, three, or four antennas.

Various embodiments relate to a method for processing received distributed multiple-input and multiple-output (DMIMO) OFDM signals from a plurality of transmitters, including: performing an initial carrier frequency offset (CFO) correction; receiving a plurality of OFDM symbols; re-constructing the channel every N symbols based upon a channel estimate for each transmitter and an estimate of residual CFO for each of the transmitters based upon the long term fields (LTF), wherein N is an integer; and equalizing the received OFDM symbols using the re-constructed channel.

A receiver for detecting and recovering payload data from a received signal is provided. The receiver includes a detector, a frequency synchronizer, and a demodulator. The receiver is configured to detect the received signal. The received signal includes the payload data and signalling data for use in detecting and recovering the payload data. The frequency synchronizer is configured to process the received signal so as to compensate for a frequency offset in the received signal. The demodulator is configured to detect the one or more first symbols and the one or more second symbols, to recover the signalling data from the one or more first symbols, and to use the signalling data to recover the payload data from the one or more second symbols. The sequence is a signature sequence associated with a transmitter of the received signal.

Embodiments of the present invention provide an communications method. For example, the apparatus receives first information that indicates a first offset from a first set of offsets, wherein the first offset is an offset from a first carrier frequency that is multiple of 100 KHz, and then obtains a carrier frequency of a cell according to the first offset indicated by the first information.

In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

In one embodiment, an apparatus includes: a baseband processor having a preamble generation circuit to generate a preamble for an orthogonal frequency division multiplexing (OFDM) transmission, the preamble generation circuit to generate the preamble having a first portion comprising a first plurality of symbols, each of the first plurality of symbols having a plurality of carriers, where a subset of the plurality of carriers have non-zero values, the preamble generation circuit to generate the non-zero values using a sequence of complex values selected to optimize a peak-to-average power ratio (PAPR); a digital-to-analog converter (DAC) coupled to the baseband processor to convert the first plurality of symbols to analog signals; a mixer coupled to the DAC to upconvert the analog signals to radio frequency (RF) signals; and a power amplifier coupled to the mixer to amplify the RF signals.

A telecommunications receiver is adapted to communicate with mobile devices that operate according to a protocol where the telecommunications receiver operates outside of expected ranges for the protocol but modifies its communications with mobile devices to appear to those mobile devices as being within the expected ranges. To determine what modifications to make to transmissions, the telecommunication receiver processes signals from mobile devices to determine where a communications channel is relative to the expected ranges and uses that information to modify transmissions to mobile devices. The expected ranges might relate to maximum distance between telecommunications receiver and a mobile device, maximum relative velocity, power etc. Determining a relative velocity, and therefore a Doppler shift, can be done by determining a fractional frequency offset, determining an expected subchannel, and determining an integer frequency offset based on the expected subchannel carrier frequency and the measured carrier frequency.

A system and method for generating a high entropy (HE) constant-envelope Gaussian minimum shift keying (GMSK) modulated signal with suppressed cyclostationary features is disclosed. In embodiments, the system includes a primary GMSK modulator for generating an initial GMSK signal based on a received data stream for transmission. The system includes a sequence of secondary GMSK modulators for generating a sequence secondary GMSK signals based on pseudorandom number sequences based on distinct chip rates. The initial GMSK signal is multiplied by the first secondary GMSK signal to generate an initial composite GMSK signal, which is sequentially multiplied by each subsequent secondary GMSK signal until a final composite GMSK signal is achieved, the final composite GMSK signal being a HE-GMSK constant-envelope signal with suppression of cyclic and cyclostationary features that might otherwise cause detection or interception of the signal.

A multi-radio border router for synchronizing communications of multiple border router radios is provided. For example, the border router includes a border router component connected to each of the plurality of border router radios. The border router component configured for selecting one of the plurality of border router radios as a master radio and assigning channel offset parameters for each of the plurality of border router radios. The master radio is configured for broadcasting synchronization beacons based on which the non-master radios synchronize their respective clocks with that of the master radio. After the synchronization, each of the border router radios communicates with endpoints associated therewith according to a channel hopping pattern modified by applying a channel offset determined based on the channel offset parameters assigned to the respective radio.

A transmitting device and a receiving device are described for a wireless communication system. The transmitting device transmits one or more synchronization signals on a carrier to at least one receiving device. A frequency of a synchronization signal among the one or more synchronization signals is located on a first frequency raster, and a carrier frequency of the carrier is deployed on a second frequency raster. The frequencies of two different synchronization signals among the one or more synchronization signals are located on different frequency positions in the first raster. The transmitting device transmits an indication of the carrier frequency to the at least one receiving device. The indication comprises at least one integer number. The receiving device derives the carrier frequency based on the at least one integer number.