1382results about "Multiple modulation transmitter/receiver arrangements" patented technology

Transmitter and receiver units for use in a communications system and configurable to provide antenna, frequency, or temporal diversity, or a combination thereof, for transmitted signals. The transmitter unit includes a system data processor, one or more modulators, and one or more antennas. The system data processor receives and partitions an input data stream into a number of channel data streams and further processes the channel data streams to generate one or more modulation symbol vector streams. Each modulation symbol vector stream includes a sequence of modulation symbol vectors representative of data in one or more channel data streams. Each modulator receives and modulates a respective modulation symbol vector stream to provide an RF modulated signal, and each antenna receives and transmits a respective RF modulated signal. Each modulator may include an inverse (fast) Fourier transform (IFFT) and a cyclic prefix generator. The IFFT generates time-domain representations of the modulation symbol vectors, and the cyclic prefix generator repeats a portion of the time-domain representation of each modulation symbol vector. The channel data streams are modulated using multi-carrier modulation, e.g., OFDM modulation. Time division multiplexing (TDM) may also be used to increase flexibility.

The invention provides a transceiver for Zigbee and Bluetooth communications integrating a Zigbee transceiver and a Bluetooth transceiver. The transceiver includes an RF processor 110, a variable bandpass filter 120, an FSK modulator / demodulator 130, a memory 140, a baseband processor 150, a main controller 160, and a channel selection / frequency hopping controller 170. The invention integrates the Zigbee transceiver and the Bluetooth transceiver so as to partially make common use of a higher layer application and a physical layer of the Zigbee transceiver and the Bluetooth transceiver. As a result, the invention has the advantage of functioning as a transceiver for Zigbee and Bluetooth communications, without causing a significant increase in size and unit price.

A pipelined digital data receiver for a cable TV headend which is capable of receiving DOCSIS 1.0 or 1.1 or advanced PHY TDMA or SCDMA bursts having programmable symbol rates and programmable modulation types as well as a host of other burst parameters such at Trellis code modulation on or off, scrambling on or off, various values for Reed-Solomon T number and codeword length. The receiver has an RF section to filter and digitize incoming RF signals. It also has an input section to detect impulse noise and do match filtering and despread SCDMA bursts. A timing recovery section recovers the symbol clock and detects the start of bursts and collisions. A rotational amplifier and equalizer calculate and track gain, phase and frequency offsets and correct symbols and calculates equalization coefficients. A decoder section decodes TCM and non TCM bursts, and a Reed-Solomon decoder section reconstructs RS codewords and uses them to error correct the payload data.

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

The present invention provides systems and methods for improved data communication between communication terminals such as a base station and an unmanned aerial vehicle. In some instances, the systems and methods described herein provide robust transmission uplink data such as control data and wideband transmission of downlink data such as image data or other sensor data, while avoiding interference between the uplink data transmission and the downlink transmission.

Embodiments are directed to transmitting L1 pre-signaling information with predetermined modulation and code rate such that L1 pre-signaling information can be received without preliminary knowledge on the network. L1 pre-signaling information makes it possible to receive the L1 signaling information, data link layer information, and notification data that may have configurable code rates and modulation. Therefore, L1 pre-signaling information can be thought of as signaling metadata (i.e., information about other signaling information). L1 signaling is divided into pre-signaling and signaling parts. The pre-signaling part includes parameters used for receiving the L1 signaling information. L1 pre-signaling signaling enables the receiver to receive the signaling itself (L1 signaling and data link layer information) by informing the receiver about the type of modulation, coding, and the like, used to transmit the L1 signaling, data link layer, and notification information.

The present invention is generally directed to methods for communicating in a dual-mode communication protocol. A representative embodiment of the present invention comprises: enabling communication in a spread-spectrum communication protocol, comprising: receiving a first portion of a communication frame at a first frequency channel, wherein the first portion of the communication frame comprises a data channel index that indicates a second frequency channel for receiving a second portion of the communication frame; switching to the second frequency channel; and receiving the second portion of the communication frame at the second frequency channel.

Emergency Location Transceivers (ELT) and communication transceivers (transmitters and receivers) for reception and demodulation of location finder signals, Global Positioning System (GPS) satellite signals and non GPS satellite location finder and other location finder signals. The received location finder signals are demodulated to location finder baseband signals. Baseband signal processors for processing single or a plurality of input signals for providing Orthogonal Frequency Division Multiplex (OFDM) baseband signals, filtered signals, cross-correlated shaped in-phase and quadrature-phase baseband signals and spread spectrum signals. Signal modulators for modulating the processed signals and for providing the modulated signals to the signal transmitter for transmission of the modulated signals. Emergency receiver systems for reception, demodulation and processing of the modulated transmitted signals. Certain emergency receiver embodiments, such as receivers of calls made to emergency call number 911 contain two or more receive antennas for reception and processing of the transmitted modulated signal. In certain embodiments emergency receiver systems have two or more receive antennas operated in a diversity mode, for reception and processing of the transmitted modulated signal.

A dual packet configuration for wireless communications including a first portion that is modulated according to a serial modulation and a second portion that is modulated according to a parallel modulation. The serial modulation may be DSSS whereas the parallel modulation may be OFDM. The first portion may include a header, which may further include an OFDM mode bit and a length field indicating the duration the second portion. The first portion may be in accordance with 802.11b to enable dual mode devices to coexist and communicate in the same area as standard 802.11b devices. The dual mode devices can communicate at different or higher data rates without interruption from the 802.11b devices. The packet configuration may include an OFDM signal symbol which further includes a data rate section and a data count section. In this manner, data rates the same as or similar to the 802.11a data rates may be specified between dual mode devices. The first and second portions may be based on the same or different clock fundamentals. For OFDM, the number of subcarriers, pilot tones and guard interval samples may be modified independently or in combination to achieve various embodiments. Also, data subcarriers may be discarded and replaced with pilot tones for transmission. The receiver regenerates the discarded data based on received data, such as using ECC techniques.

A method and apparatus for efficiently selecting a demodulation scheme for a particular channel in a digital broadcast receiver supporting a plurality of demodulation schemes are provided. The method includes receiving the digital broadcast signal of the channel; attempting demodulation of the digital broadcast signal using a demodulation scheme corresponding to a sequential index; and if the demodulation attempt succeeds, restoring data and if the demodulation attempt does not succeed, attempting demodulation again using a demodulation scheme corresponding to a next sequential index.

A system and method for transmitting control information and data to a mobile station in a communication system using adaptive antenna technology defined in a broadband wireless communication system. In a method for transmitting and receiving information data in the wireless communication system, a base station separates information data to be transmitted into control information and user data, applies different modulation and coding schemes to the control information and the user data, and transmits the information data to an associated mobile station. The mobile station identifies the modulation and coding schemes of the information data received from the base station and demodulates a total of the information data according to the modulation and coding schemes, or independently demodulates the control information and the data according to the modulation and coding schemes.

In a multi-user frequency domain spreading downlink MC-CDMA system. a group of sub-carriers can be replaced by an equivalent sub-carrier of a conventional OFDM modem for purposes of resource allocation to improve the system performance. The chips for a given user are spread only within the group. Confinement insures synchronization between different users' chips that is essential to the recovering and separation of user symbols at the receiver. There is no limit imposed on the group size, which permits different spreading code lengths to be used for different scenarios or for performance tuning.

An apparatus and method for controlling wireless communication signals is provided, in which a wireless transmitter in a communication network generates a signal carrying data for wireless transmission, and is capable of varying the data carrying capacity of the wireless transmission channel in response to the quantity of data received for wireless transmission. A monitor is provided to monitor the quantity of received data and the capacity of the communication channel is increased if the monitored quantity exceeds a predetermined threshold. The capacity of the communication channel can be varied by varying the level of modulation and / or by varying the level of code inserted into the data stream. The output power of the wireless transmission signal may be varied in response to the quantity of received data.

A digital receiver for a burst-mode wireless communication system, such as a Bluetooth system comprises a radio frequency input stage for receiving an input signal and an analogue-to-digital converter for converting the input signal from an analogue signal to a digital signal. A switch is coupled to the analogue-to-digital converter and a first signal processor is coupled to the switch and is arranged to demodulate signals modulated according to a first modulation process, such as a GFSK modulation process. A second signal processor is also coupled to the switch and is arranged to demodulate signals modulated according to a second modulation process, such as π / 4DQPSK modulation process or an 8DPSK modulation process. The switch is arranged to switch the digital signal between the first and second signal processors to recover signals from the first and / or the second modulation process. A method for processing received signals in a burst-mode wireless communication system is also disclosed.

Modulation Demodulation (Modem) Format Selectable (MFS) and Code Selectable (CS) systems for new generations of wireless systems, including third generation “3G”, spread spectrum systems, CDMA,W-CDMA and GSM, OFDM systems having different bit rates, that is having bit rate selection or bit rate agile( BRA) operation. MFS and Code Selectable (CS) systems connected to one or more modulators, one or more transmit amplifiers and one or more antennas. The transmitted signals are received by single or multiple receivers and demodulators.Shaped Time Constrained Signal(TCS) wavelet processors and bit rate agile Long Response (LR) filters provide shaped Time Constrained Signal (TCS) waveforms / filtered signals in in-phase(I) and quadrature-phase(Q) baseband channels to one or more Quadrature Modulators(QM) connected to the baseband signal processing network. A control processor and signal selection device selects one or more of the baseband signals and provides these signals through one or more quadrature modulators(QM) having the same or different radio frequency(RF) signals for amplification by one or more amplifiers. A selection device for selecting a Linearly and / or a Non-Linearly Amplified (NLA) modulated signal is provided and the selected amplified signal is provided to one or more transmit antenna systems or to one or more transmission media.

A transmitting apparatus, receiving apparatus, communication system, and a signal processing method of each applying a suitable modulation method and transmission path estimation method in accordance with characteristics of the transmission information for improving the transmission efficiency operate so that at the transmission side, the ratio of adding transmission path estimation pilot symbols is suitably controlled in accordance with an aspect of the dat transmitted, for example, the size of the packets transmitted and the state of the transmission path, wherein the transmission data is mapped by the selected modulation method, and the signal is processed in accordance with the method of estimation of the transmission path, and the transmission signal is produced by inverse fast Fourier transform processing and transmitted. At the reception side, the received signal is fast Fourier transformed, the transmission path is estimated by the transmission path estimation method selected at the transmission side, the received signal is correct in accordance with result, and the received data is reproduced in accordance with the modulation method. Therefore, it is possible to always adopt the optimum transmission method in accordance with the attribute of the transmission data etc. and possible to realize an improvement of a transmission efficiency and an enhancement of the quality of communication.

A reciprocating pulser system for generating pressure fluctuations in a flowing drilling fluid comprising a reciprocating poppet and a stationary valve assembly with axial flow passages. The poppet reciprocates in close proximity to the valve assembly, at least partially blocking the flow through the valve assembly and generating oscillating pressure pulses. The poppet passes through two zero speed positions during each cycle, enabling rapid changes in signal phase, frequency, and / or amplitude thereby facilitating enhanced data encoding. The poppet is driven by a linear electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. In one embodiment, a force balance spring is used to essentially offset the hydraulic flow forces on the poppet. In one embodiment, a bypass poppet is used to adjust the differential pressure across the valve assembly.

Disclosed is an adaptable / variable type modulation / demodulation apparatus. A physical layer transmission apparatus for adaptable / variable type modulation, the transmission apparatus including a classification unit to classify a bit stream according to a standard that is determined in advance after receiving the bit stream, an uncoded bit group unit to group the bit stream not to be LDPC-coded by a predetermined number of bits, an LDPC encoder to perform LDPC-coding of the bit stream, a coded bit group unit to group the coded bit stream by the predetermined number of bits, a quadrature amplitude modulation (QAM) unit to select a symbol coset using the coded bit groups; and a convolutional interleaver to perform convolutional interleaving of the symbol.

A remote radio head unit (RRU) system for multiple operating frequency bands, multi-channels, driven by a single or more wide band power amplifiers. More specifically, the present invention enables multiple-bands RRU to use fewer power amplifers in order to reduce size and cost of the multi-band RRU. The present invention is based on the method of using duplexers and / or interference cancellation system technique to increase the isolation between the transmitter signal and receiver signal of the RRU.

A unified and flexible signaling method and radio interface accommodate different multiple access schemes, e.g, FDMA, TDMA, CDMA, OFCDM, and IFDMA. Each user data unit is associated with one of several different multiple access techniques that defines how multiple users access communication resources. Each user data unit is processed into discrete samples, where the discrete samples for each user data unit are assigned to one or more respective discrete signal blocks. Discrete samples associated with different multiple access techniques are processed and grouped together into a time slot or packet for transmission over a communication channel.

A method implemented by a Wireless Transmit / Receive Unit (WTRU) includes receiving a DeModulation Interference Measurement (DM-IM) resource, determining an interference measurement based on the DM-IM resource, and demodulating a received signal based on the interference measurement. An interference is suppressed based on the interference measurement. At least one DM-IM resource is located in a Physical Resource Block (PRB). The DM-IM resource is located in a PRB allocated for the WTRU. The DM-IM resource is a plurality of DM-IM resources which form a DM-IM pattern, and the DM-IM pattern is located on a Physical Downlink Shared Channel (PDSCH) and / or an enhanced Physical Downlink Shared Channel (E-PDSCH) of at least one Long Term Evolution (LTE) subframe. The DM-IM resources are different for different Physical Resource Blocks (PRB) in the LTE subframe. The DM-IM is located in a Long Term Evolution (LTE) Resource Block (RB), and the DM-IM pattern is adjusted.

A process is described to build physical layer frames with a modcode adapted to the signal quality of a destination terminal. Data packets assigned to the same modcode may be sent in the same frame, although packets associated with higher modcodes may be used to complete a frame before switching to the applicable higher modcode for construction of subsequent frames. After an interval, the order of progression is restarted with an out of order packet above a threshold age. Flow control filtering mechanisms and a variable reliability margin may be used to adapt dynamically to the current data traffic conditions.

A radio frequency identification (RFID) device, locator, wired and / or wireless communicator system comprising one or more than one antennas for receiving Radio Frequency (RF) signals from one or more RFID and or location determining and / or communication transmitters. The system has one or more receivers and demodulators for reception and demodulation of signals to baseband signals. A processor circuit processes the baseband signals and provides them to a cross-correlator circuit for cross-correlating the processed baseband signals and for generation of cross-correlated baseband signals. One or more modulators modulate the baseband signals and provide them to one or more transmitters. circuitry.

A transmitter system is provided. In one embodiment, the transmitter system includes a data modulation unit, which generates a stream of data that is synchronized with a master clock. The transmitter system additionally includes a transmitter that transmits the stream of synchronized data by way of an attached antenna. In another embodiment the transmitter system includes a Medium Access Control (MAC) layer that includes a clock synchronization device, a frequency divider, a slot allocation unit, and a multiplexer / demultiplexer. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

To perform link adaptation at radio interfaces of an enhanced packet data cellular network the system behavior is simulated for different C / I conditions. Two sets of tables are obtained, each table including upgrade and downgrade thresholds expressed in terms of Block Error Rate (BLER). The tables are specialized for taking into account EGPRS type II hybrid ARQ, Incremental Redundancy (IR). Transmitted blocks are checked for FEC and results are sent to the network that continuously updates BLER. A reliability filter output is used to decide the weight between new and old measurements. IR efficiency is tested for each incoming block and an indicative variable IR_status is filtered. Each threshold of BLER to be used is obtained by linear interpolation between the tabulated threshold without IR and with perfect IR, both weighed with filtered IR_status. Filtered BLER is compared with interpolated thresholds for testing the incoming of a MCS switching condition.

Modulation-demodulation format selectable (MFS) processor, cross-correlator and transmit filter for processing, cross-correlating and filtering in-phase and quadrature-phase baseband signal and providing a first bit rate and a second bit rate baseband signal to a modulator and a transmitter for modulation and transmission of the processed filtered baseband signal. Transmit amplifier operated in a first radio frequency (RF) band for amplification of the first bit rate modulated signal and a second RF amplifier operated in a second RF band for amplification of the second bit rate modulated signal. Switch for selecting the first or the second bit rate or first or second modulation format signal and providing selected signal to a transmitter. Receiver for receiving transmitted signal. Demodulator and demodulator filter mis-matched to transmit baseband filter. Receive processor for receiving and processing quadrature demodulator demodulated baseband filtered signal and for providing first and second format cross-correlated in-phase and quadrature-phase baseband signal. Time division multiplex (TDM) and Orthogonal Frequency Division Multiplex (OFDM) processor and transmit baseband filter for processing, filtering and providing TDM and OFDM processed and filtered signal to a modulator, transmitter and receiver. Receiver and demodulator for demodulating and baseband filtering received modulated TDM signal. Demodulator of TDM signal has a demodulator baseband filter which is mis-matched to the transmit baseband filter and provides demodulated baseband mis-matched filtered cross-correlated in-phase and quadrature-phase signal.