Included are a demodulation unit 20 that demodulates a received OFDM modulation signal to acquire a demodulated constellation signal, an ideal constellation signal generation unit 312 that generates an ideal constellation signal from the demodulated constellation signal, a data extraction unit 313 that extracts signal data included in some symbol sections including a known reference symbol, among all symbol sections, from the demodulated constellation signal and the ideal constellation signal, a phase error calculation unit 314 that calculates the phase error of the demodulated constellation signal for the ideal constellation signal, with respect to the extracted signal data, a phase error characteristics estimation unit 315 that estimates the frequency characteristics of the phase error, and a phase error correction unit 316 that corrects the phase error of the demodulated constellation signal, based on the frequency characteristics of the phase error.

A method of auto-detection of WLAN packets includes selecting a first Golay sequence from a first pair of Golay complementary sequences associated with first packet type, each Golay sequence of the first pair of Golay complementary sequences being zero correlation zone (ZCZ) sequences with each Golay sequence of a second pair of Golay complementary sequences associated with a second packet type, and transmitting a wireless packet carrying a short training field (STF) that includes one or more instances of the first Golay sequence.

Included are a demodulation unit 20 that demodulates a received OFDM modulation signal to acquire a demodulated constellation signal, an ideal constellation signal generation unit 312 that generates an ideal constellation signal from the demodulated constellation signal, a data extraction unit 313 that extracts signal data included in some symbol sections including a known reference symbol, among all symbol sections, from the demodulated constellation signal and the ideal constellation signal, a phase error calculation unit 314 that calculates the phase error of the demodulated constellation signal for the ideal constellation signal, with respect to the extracted signal data, a phase error characteristics estimation unit 315 that estimates the frequency characteristics of the phase error, and a phase error correction unit 316 that corrects the phase error of the demodulated constellation signal, based on the frequency characteristics of the phase error.

A transmitter for transmitting payload data and emergency information using data symbols in a single-carrier or multi-carrier broadcast system comprises a modulator configured to modulate one or more transmission symbols with signaling data for use in detecting and recovering the payload data at a receiver and to modulate one or more transmission symbols with the payload data. An emergency information receiver receives emergency information carrying information of an actual emergency. An emergency information embedder embeds emergency information into one or more transmission symbols, wherein the emergency information is embedded within a predetermined time period after its reception by using a resource used for carrying signaling data and/or payload data if no emergency information shall be transmitted. A transmission unit transmits the transmission symbols.

A method for indicating a frame structure, a method for updating a frame structure, and related devices are provided. The method for indicating a frame structure, performed by a first device, includes: determining a first frame structure based on user data to be transmitted; and when the first frame structure is different from a second frame structure corresponding to a second device, sending indication information, where the indication information is used to indicate the first frame structure.

Disclosed is a pilot sequence transmission method for generating a BSS composed of a plurality of pilot sequences, and selectively generating an SSS, to be used with the BSS, according to a channel environment such that additional information is transmitted through a pilot sequence selected from a sequence set having the BSS and the SSS. Furthermore, also disclosed is a pilot sequence identification method analyzing a pilot sequence transmitted by a transmitter, so as to obtain additional information.

A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined phase-estimate to one of the M symbols.

A method and apparatus for zero interference multi-gigabit inter-satellite communication between system satellites (300) and client satellites (301) using millimeter wave beams at transmit and receive frequencies that are aligned to the peak atmospheric molecular absorption frequencies in the electromagnetic spectrum (FIG. 1). The narrow low power beams are accurately steered within a restricted set of directions (FIG. 5) that prevent interference to other space borne radio receivers whether in geostationary or low earth orbits and cannot interfere with terrestrial receivers due to atmospheric absorption. The apparatus comprises an integrated electronically steered 2-D phased array (401), transceiver and baseband integrated circuits (402, 403) with a beam controller (404) coupled to the spacecraft attitude determination and control subsystem (407), central processing unit (406) and solid state storage device (405).

A transmitter for transmitting payload data and emergency information using data symbols in a single-carrier or multi-carrier broadcast system includes a modulator configured to modulate one or more transmission symbols with signaling data for use in detecting and recovering the payload data at a receiver and to modulate one or more transmission symbols with the payload data. An emergency information receiver receives emergency information carrying information of an actual emergency. An emergency information embedder embeds emergency information into one or more transmission symbols, wherein the emergency information is embedded within a predetermined time period after its reception by using a resource used for carrying signaling data and/or payload data if no emergency information shall be transmitted. A transmission unit transmits the transmission symbols.

A technique of separating a sequence of modulation shift keying (MSK) symbols into a first portion and a second portion and separately comparing the first portion of the sequence of MSK symbols and the second portion of the sequence of MSK symbols against a first portion of a reference sequence of MSK symbols and a second portion of the reference sequence of MSK symbols allows a low complexity detection of a start field delimiter in a wireless communication packet.