A multi-carrier cellular wireless network (400) employs base stations (404) that transmit two different groups of pilot subcarriers: (1) cell-specific pilot subcarriers, which are used by a receiver to extract information unique to each individual cell (402), and (2) common pilots subcarriers, which are designed to possess a set of characteristics common to all the base stations (404) of the system. The design criteria and transmission formats of the cell-specific and common pilot subcarriers are specified to enable a receiver to perform different system functions. The methods and processes can be extended to other systems, such as those with multiple antennas in an individual sector and those where some subcarriers bear common network/system information.

The invention concerns a method for conditioning a multicarrier transmit signal using a first or a second set of subgroups of time-frequency resource elements, with a subgroup of the first set of subgroups and a subgroup of the second set of subgroups having common time or frequency resources and being neighbored in time or frequency, wherein a first filter module (FILT1) filters the first set of subgroups using a first filter characteristic by a first set of filter coefficients, and a second filter module (FILT2) filters the second set of subgroups using a second filter characteristic by a second set of filter coefficients, and a base station and a transmitter apparatus (TA) therefor.

Methods and systems for signal transmission in millimeter wave (mmW) range. A set of sequences is used to encode a data signal for one layer in a group of layers. Each sequence in the set of sequences has a length equal to the number of resources shared among the group of layers. At least a portion of the sequences have a low density of non-zero values, and the non-zero values are assigned to a subset of the shared resources. Each sequence assigns a non-zero value to at most one resource of the subset of shared resources, and all non-zero values assigned by all sequences have equal power amplitudes.

This disclosure provides methods, devices and systems for improving the security of secure long training field (LTF) transmissions. In some implementations, a transmitting device may perform windowing on a secure LTF, in the frequency domain, so that the resulting time-domain LTF signal is difficult, if not impossible, to predict by any device that observes a portion of the LTF signal. In some aspects, the transmitting device may negotiate the windowing of secure LTFs with a receiving device based on fine timing measurement (FTM) negotiation frames exchanged at the start of an FTM procedure. In some other aspects, the transmitting device may dynamically or adaptively perform windowing on secure LTFs. In such aspects, the transmitting device may indicate whether windowing is performed on a secure LTF based on information carried in a signal field of a physical layer convergence protocol (PLCP) protocol data unit (PPDU) that includes the secure LTF.

A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension N×N, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.

Circuitry includes: a resonant circuit for receiving a radio frequency signal; a rectifier outputting a first rectified signal matching a portion of the radio frequency signal and a second rectified signal having portion that matches the radio frequency signal and is out of phase with the first rectified signal; a clock regenerator circuit outputting a clock waveform corresponding to the first and second rectified signals; an oscillator timing circuit forming a first sloped waveform having a linear slope and a second sloped waveform having a linear slope, and comparators to compare the first sloped waveform and the second sloped waveform. The oscillator timing circuit outputs a master clock signal having transitions when the first and the second sloped waveform have equal magnitudes. A pluck pulse generator forms a pulse of a predetermined length when the master clock signal transitions.

There is provided a method for processing a set of input symbols. The method is performed by a transmitter. The method comprises acquiring a set of input symbols. The method comprises generating a set of precoded symbols from the set of input symbols by subjecting the set of input symbols to a coding vector. The method comprises generating a transmission signal comprising a sequence of pulse forms from the set of precoded symbols by pulse shaping the set of precoded symbols. The coding vector is based on a model vector modelling intersymbol interference experienced by the pulse forms.

A pulse shaping circuit is configured to shape a waveform of an edge of a signal applied to a switch of a power amplifier included in an on-off keying transmitter.

According to one embodiment, a synchronization circuit includes a received-signal detecting unit which detects a received signal including a first and a second reference signal, a timing-synchronization adjusting unit including a storage module storing information of the first reference signal and a correlation operating module carrying out correlation operation of the first reference signal included in the received signal and the information of the first reference signal output from the storage module, the timing-synchronization adjusting unit which carries out timing synchronization so that a result of the correlation operation carried out by the correlation operating module becomes a predetermined value, and a phase-synchronization adjusting unit which carries out phase synchronization of a subcarrier by adjusting a component varied depending on a phase of a subcarrier frequency by using a phase modulation signal included in the second reference signal, wherein the received signal is a filtered multicarrier signal.

A circuit is provided for ringing suppression. The circuit comprises a termination resistor coupled to a bus via a switch; and a control circuit. The control circuit comprises an input coupled to a data input pin of a bus transceiver and an output coupled to control the termination resistor. The circuit is configured to selectively couple the resistor to the bus in response to a transition on the input bit stream.