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.

A sequence-based signal processing method and apparatus are provided. A sequence meeting a requirement for sending a signal by using a physical uplink control channel (PUCCH) is determined, where the sequence is a sequence {f.sub.n} consisting of N elements, f.sub.n is an element in the sequence {f.sub.n}, and the determined sequence {f.sub.n} is a sequence meeting a preset condition; then, the N elements in the sequence {f.sub.n} are respectively mapped to N subcarriers to generate a first signal; and the first signal is sent. By using the determined sequence, when a signal is sent by using a PUCCH, a low sequence correlation can be maintained, and a relatively small peak-to-average power ratio (PAPR) value and cubic metric (CM) value can also be maintained, thereby meeting a requirement of a communication application environment in which a signal is sent by using a PUCCH.

A user equipment (UE) in a wireless network employs orthogonal polyphase codes for encoding data symbols to generate a set of coded data symbols, which are modulated onto Orthogonal Frequency Division Multiplex (OFDM) subcarrier frequencies assigned for use by the UE, and the resulting OFDM signal is transmitted to a base station in the wireless network. The orthogonal polyphase codes include pairs of orthogonal polyphase codes that are complex conjugates of each other.

Disclosed are a method and a device for transmitting data based on different pilot tone patterns in a wireless LAN. The method for transmitting data based on the different pilot tone patterns in a wireless LAN may comprise the steps of: an AP transmitting, to a first STA, a first data field generated based on a first pilot tone pattern, from a first frequency bandwidth; and the AP transmitting, to a second STA, a second data field generated based on a second pilot tone pattern, from a second frequency bandwidth, wherein the size of the first frequency bandwidth is n times larger than the size of the second frequency bandwidth, the size of IFFT applied to the first data field and the size of IFFT applied to the second data field are identical, the first pilot tone pattern includes a plurality of first pilot tones, wherein the plurality of first pilot tones are respectively allocated to each of a plurality of first pilot tone indexes, the second pilot tone pattern includes a plurality of second pilot tones, wherein the plurality of second pilot tones are respectively allocated to each of a plurality of second pilot tone indexes, and wherein a portion of the first pilot tone indexes may be identical to the plurality of second pilot tone indexes.

A base station may multiplex a peak suppression information message (PSIM) on a physical downlink shared channel (PDSCH) with data for efficient implementation of PSIMs for peak to average power ratio (PAPR) reduction. A base station may clip peaks from a signal to be transmitted and capture information of the clipped peaks into a PSIM. The base station may then multiplex the PSIM on the PDSCH such that a receiving device (for example, a user equipment (UE)) may receive the signal and reconstruct the signal (for example, PDSCH data) using the PSIM. According to some aspects, each PDSCH symbol may include a PSIM for a previous PDSCH symbol, or the PSIM may be for the current symbol. Various aspects of the techniques described herein may further provide for PSIM positioning in frequency, PSIM modulation, PSIM channel coding, PSIM multiple-input multiple-output (MIMO) configurations, among other examples.

A system implementing a distributed communication system consisting of assignable common equipment using centrally located processors for performing data network services, bidirectional route-able communications link from common equipment to distributed equipment, and distributed equipment located near subscribers. Data network services are combination of wireline for use on a wired connection to a subscriber and wireless for use on radio connection to a subscriber. Data network services include protocol and modulation processing for the relevant wired or wireless communications standard. The distributed equipment used to send and receive signals to plurality of subscribers. The distributed equipment may support both wireline and wireless subscribers or may have separate subsystems for each.

Embodiments herein provide an OFDMA method for performing OFDM based communication in a wireless communication system. The OFDMA method includes splitting a carrier bandwidth into a number of subbands and modulating resource units in each of the subbands with data symbols in a parallel manner Further, multiplexing the resource units by transforming each of the modulated resource units through a plurality of unitary transformations at a stage. Further, generating an output by performing a parallel to serial conversion of the transformed resource units. Further, the OFDMA method includes generating an OFDM signal by multiplexing an output from at least one of the previous stage to another stage by transforming the output through a unitary transformation for a defined number of times. Furthermore, the OFDMA method includes transmitting the OFDM signal over a wireless channel in the wireless network system.

Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection. Pilot symbol mapping is provided for forming pilot carriers by assigning orthogonal sequences to corresponding subcarriers among OFDM signals which are transmitted at the same time from respective antennas in the time domain. Even when pilot symbols are multiplexed among a plurality of channels (antennas), this allows frequency offset/phase noise to be estimated with high accuracy.

A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals, the apparatus comprises an encoder for encoding service data corresponding to each of a plurality of data transmission path, wherein each of the data transmission path carries at least one service component, a frame builder for building at least one signal frame included in a super frame, wherein each of signal frames includes the encoded service data and the encoded signaling data, a modulator for modulating the at least one signal frame by an OFDM (Orthogonal Frequency Division Multiplex) scheme, wherein each of the modulated signal frame includes a preamble having basic transmission parameters, wherein a length of the preamble is extendable and a transmitter for transmitting the broadcast signals carrying the at least one modulated signal frame.

A method for transmitting data via a coaxial electrical cable includes (a) converting symbols of each input data stream of a plurality of parallel input data streams from digital form to analog form, (b) individually filtering symbols of each input data stream, (c) transforming symbols of each input data stream from a first frequency-domain to a first time-domain, to generate parallel first time-domain samples, (d) converting the first time-domain samples to a serial multi-carrier signal, and (e) injecting the multi-carrier signal onto the coaxial electrical cable.