1053 results about "Frequency-division multiplexing" patented technology

A system and method for supplying power to a headset, and for transmitting multiple signals generated in the headset to a terminal using frequency division multiplexing. An audio signal and a carrier signal are generated in the terminal and summed together to form a composite uplink signal. The composite uplink signal is provided to a headset over a first physical channel. At the headset, the audio and carrier signals are separated, and the carrier signal is used to generate power in the headset. Signals generated by a plurality of acoustic sensors in the headset are combined using frequency division multiplexing to generate a composite downlink signal, which is transmitted to the terminal over a second physical channel. One or more carrier signals used to generate the composite downlink signal are provided by either a carrier source in the headset, or by recovering the carrier signal from the composite uplink signal.

A device, network and method wherein a standard wireless modem is coupled to wiring for carrying a wireless baseband signal that may be OFDM based, and may be directly generated by the wireless IF modem, or extracted from the modem RF signal. The wiring may be a building utility wiring, such as telephone, AC power or CATV wiring. The baseband signal is carried simultaneously with the utility service signal over the utility wiring using Frequency Division Multiplexing. The device may be enclosed with a data unit, a standalone dedicated enclosure, within an outlet or as a plug-in outlet adapter. Data units may couple the device by a wiring port such as standard data connector, or via wireless connection. The device may be locally powered or via a power signal carried over the wiring. This abstract is not intended to limit or construe the scope of the claims.

A method is described for operating a cellular network, where the cellular network uses a plurality of frequency division multiplexing (FDM) bands for wireless communication from user equipment (UE) to a base station (NodeB). At least one band-specific cell parameter is computed for at least one the plurality of FDM bands by a serving NodeB. The band-specific cell parameters are transmitted from the NodeB serving a first cell to a NodeB serving a second cell. The band-specific cell parameters may be computed in response to scheduling information and / or channel specific measurements made by the NodeB. A UE receives a first Power Configuration, a Second Power Configuration, and a Scheduling Message indicative of an FDM band from the set comprising at least from First FDM band and Second FDM band. UE transmits with the First Power Configuration if the Scheduling Message was indicative of First FDM band, and with the Second Power Configuration otherwise.

A method and system for providing broadband access to a data network via gas pipes is disclosed. Embodiments of the present invention utilize Orthogonal Frequency-Division Multiplexing (OFDM) or Frequency-Division Multiplexing (FDM) as a modulation technique in order to protect against the effects of dispersion in the gas pipes. An OFDM transceiver modulates a digital data stream into an OFDM signal, RF up-converts the OFDM signal, and transmits the RF up-converted OFDM modulated signal through a gas pipe.

A method of coordinating resources for repetition of random access bursts performed by a mobile terminal, the method comprising: determining groups of access slots based on parameters from a network, wherein each access slot is defined by any combination of frequency, time and code, and the access slots are organized according to a frequency pattern; transmitting an access burst on an access slot from a chosen group of access slots; and re-transmitting the access burst on the next access slot from the chosen group of access slots.

A device, network and method wherein a standard wireless modem is coupled to wiring for carrying a wireless baseband signal that may be OFDM based, and may be directly generated by the wireless IF modem, or extracted from the modem RF signal. The wiring may be a building utility wiring, such as telephone, AC power or CATV wiring. The baseband signal is carried simultaneously with the utility service signal over the utility wiring using Frequency Division Multiplexing. The device may be enclosed with a data unit, a standalone dedicated enclosure, within an outlet or as a plug-in outlet adapter. Data units may couple the device by a wiring port such as standard data connector, or via wireless connection. The device may be locally powered or via a power signal carried over the wiring. This abstract is not intended to limit or construe the scope of the claims.

A novel mechanism for simultaneous multiple signal reception and transmission using frequency multiplexing and shared processing. Multiple RF signals, which may be of various wireless standards, are received using one or more shared processing blocks thereby significantly reducing chip space and power requirements. Shared components include local oscillators, analog to digital converters, digital RX processing and digital baseband processing. In operation, multiple RX front end circuits, one for each desired wireless signal, generate a plurality of IF signals that are frequency multiplexed and combined to create a single combined IF signal. The combined IF signal is processed by a shared processing block. Digital baseband processing is performed on each receive signal to generate respective data outputs. Further, simultaneous full-duplex transmission and reception is performed using a single local oscillator. The phase / frequency modulation of the frequency synthesizer used in the TX is removed from the local oscillator signal for use in the receiver.

An oversampling pulse oximeter includes an analog to digital converter with a sampling rate sufficient to take multiple samples per source cycle. In one embodiment, a pulse oximeter (100) includes two or more light sources (102) driven by light source drives (104) in response to drive signals from a digital signal processing unit (116). The source drives (104) may drive the sources (102) to produce a frequency division multiplex signal. The optical signals transmitted by the light sources (102) are transmitted through a patient's appendage (103) and impinge on a detector (106). The detector (106) provides an analog current signal representative of the received optical signals. An amplifier circuit (110) converts the analog current signal to an analog voltage signal in addition to performing a number of other functions. The amplifier circuit (110) outputs an analog voltage signal which is representative of the optical signals from the sources (102). This analog voltage signal is received by a fast A / D converter (112) which samples the analog voltage signal to generate a digital voltage signal which can be processed by the digital signal processing unit (116). The fast A / D converter (112) operates at a rate sufficient to take multiple samples per source cycle and may have a sampling frequency, for example, of over 41 kHz. The digital signal processing unit (116) implements software for averaging the samples over a source cycle for improved measurement consistency, improved signal to noise ratio and reduced A / D converter word length.

A method and apparatus for combining space-frequency block coding (SFBC), spatial multiplexing (SM) and beamforming in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. The system includes a transmitter with a plurality of transmit antennas and a receiver with a plurality of receive antennas. The transmitter generates at least one data stream and a plurality of spatial streams. The number of generated spatial streams is based on the number of the transmit antennas and the number of the receive antennas. The transmitter determines a transmission scheme in accordance with at least one of SFBC, SM and beam forming. The transmitter transmits data in the data stream to the receiver based on the selected transmission scheme.

An OFDM system uses a normal mode which has a symbol length T, a guard time TG and a set of N sub-carriers, which are orthogonal over the time T, and one or more fallback modes which have symbol lengths KT and guard times KTG where K is an integer greater than unity. The same set of N sub-carriers is used for the fallback modes as for the normal mode. Since the same set of sub-carriers is used, the overall bandwidth is substantially constant, so alias filtering does not need to be adaptive. The Fourier transform operations are the same as for the normal mode. Thus fallback modes are provided with little hardware cost. In the fallback modes the increased guard time provides better delay spread tolerance and the increased symbol length provides improved signal to noise performance, and thus increased range, at the cost of reduced data rate.

A communications device includes a demapping and demodulation circuit that demaps and demodulates an OFDM communications signal as modulated subcarriers carrying communications data and modulated subcarriers carrying a training sequence forming a preamble that includes a long sync sequence for channel and frequency offset estimation having a extended guard interval (GI). The OFDM subcarriers carrying the training sequence have a quadratic modulation to produce a low peak-to-average power (PAPR) preamble with PAPR of approximately 2.6 decibels (dB). A channel estimate circuit is positioned to receive signals after processing within a FFT circuit and subcarrier demapper circuit and estimates the channel characteristics of the communications channel based on splitting the extended guard interval from the long sync sequence and processing into values that represent the low PAPR preamble as plus or minus one (±1) values in a real or imaginary component as adds and subtracts.

A method is described for operating a cellular network, where the cellular network uses a plurality of frequency division multiplexing (FDM) bands for wireless communication from user equipment (UE) to a base station (NodeB). At least one band-specific cell parameter is computed for at least one the plurality of FDM bands by a serving NodeB. The band-specific cell parameters are transmitted from the NodeB serving a first cell to a NodeB serving a second cell. The band-specific cell parameters may be computed in response to scheduling information and / or channel specific measurements made by the NodeB. A UE receives a first Power Configuration, a Second Power Configuration, and a Scheduling Message indicative of an FDM band from the set comprising at least from First FDM band and Second FDM band. The UE transmits with the First Power Configuration if the Scheduling Message was indicative of First FDM band, and with the Second Power Configuration otherwise.

A multi-antenna communication method of a frequency division multiplexing system of a time division duplex is characterized in that a generalized beam area is arranged in a downstream area of a unit frame; the generalized beam area is divided to M plus N generalized beam subsections in a frequency domain, and a pilot channel which is composed of a subcarrier or a plurality of subcarriers is arranged in each generalized beam subsection; a pilot channel to which a pre-coding vector UI conducts the pre-coding is sent by a base station in the I generalized beam subsection; wherein, M of the pre-coding vector UI are different MIMO pre-coding vectors which are used in a large-angle expand channel and based on the latent beam forming, N of the pre-coding vector UI are pre-coding vectors which are used in a small-angle expand channel and based on the beam forming direction, and pre-coding vector index is I is equal to 1, 2,..., M+N; and the frequency division multiplexing system is a single carrier or multi-carrier transmission system which is based on a frequency division multiplexing technology.