5255results about "Modulated-carrier systems" patented technology

A broadband service communication system using an MV cable for conveying RF signals in a network segment, which includes a distribution center (PLT controller) and a plurality of power line telecommunication (PLT) stations. The PLT controller has a distribution modem for conveying downstream and upstream RF signals to and from the PLT stations through the MV cable via couplers. Each PLT station has a modem for conveying the downstream and upstream RF signals via couplers and for conveying media signals to one or more customer premises equipment (CPE) via, e.g. wireless links. The PLT controller controls each PLT station regarding upstream communications transfer of all downstream communications and also controls. The PLT controller can be connected via a router to a WAN to convey media signals to and from the WAN. Repeaters and interlinks are used to join multiple network segments.

A system and machine-implemented method are described for performing precoding interpolation in a DIDO system which employs orthogonal frequency-division multiplexing (OFDM) and DIDO precoding to communicate with a plurality of distributed-input-distributed-output (DIDO) clients. For example, a system according to one embodiment of the invention comprises: selecting a first subset of ODFM tones to determine a first subset of precoding weights; deriving a second subset of precoding weights for a second subset of ODFM tones by interpolating between the first subset of precoding weights; and using a combination of the first subset of precoding weights and the second subset of precoding weights to precode a data stream prior to transmitting the data stream to a DIDO client.

Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of "transmission channels" at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be "pre-conditioned" and prior to transmission.

The present invention provides a system for operating a power line communications system that is comprised of a plurality of network elements, which may take the form of repeaters, bypass devices, backhaul devices, wireless backhaul devices, enhanced bypass device, communication interface devices and others. In one embodiment, two groups of network elements in the same electrical distribution system are isolated except selected communication link.

An improved method for delivery and play back of sound and image files is provided. This new method includes the use of sound and/or image clips, which can be snippets or full files, as alerts for a variety of electronic devices or for playing on a handheld device, and for use as a promotion to sell items associated with the files. A collection or library of uniquely selected and/or edited clips may also be provided to the consumer in a manner far more conveniently on conventional telephone equipment than previously available. Algorithms are provided for the delivery, storage and playback of the sound files, including a delivery method algorithm (500), a parametric optimization and compression algorithm (1500), and an error correction algorithm. In contrast to the conventional ring tones or musical chimes used to ring cellular phones currently on the market, the current invention provides a method for ringing cellular phones and landline telephones with real sound recordings including real music, which may be songs lifted from copyright registered CD tracks, and may comprise human voice, various instrument sounds, and other sound effects of a high quality. A software based system for encoding the hardware of existing cellular phones at the time of manufacturing with delivery, storage, and playback capabilities in accordance with the present invention is provided, such that additional hardware is not required.

A wireless communication includes a base station that configures a set of non-zero power reference signals corresponding to multiple potential transmission points to one or more users equipment UEs and configures at least one zero-power reference signal, with zero transmission power from one or more of the multiple transmission points. The base station transmits configuration information to at least one UE of the one more UEs, wherein the configuration information corresponds to a set of resource elements that are associated with a set of channel state information reference signals and wherein the set of channel state information reference signals include the set of nonzero-power reference signals and the at least one zero-power reference signal. The UE then performs a channel measurement based on one or more non-zero-power reference signals of the set of non-zero-power reference signals and performs an interference measurement based on the at least one zero-power reference signal.

A wireless terminal receives signaling information, pertaining to a reference signal transmission in at least one specifically designated sub frame, the signaling information including a list, the list including base station identities. The terminal determines, from at least one of the base station identities in the list, the time-frequency resources associated with a reference signal transmission intended for observed time difference of arrival (OTDOA) measurements from a transmitting base station associated with said one base station identity. The time of arrival of a transmission from the transmitting base station, relative to reference timing, is measured. The wireless terminal can receive a command from a serving cell to start performing inter-frequency OTDOA measurement on a frequency layer containing reference signals, the frequency layer distinct from the serving frequency layer, the serving frequency layer not containing positioning reference signals. The wireless terminal can perform OTDOA measurements subsequent to the reception of the command on a carrier frequency different from the serving cell carrier frequency. A base station transmitter can jointly schedule a reference signal transmission from a plurality of base station transmitters for the purpose of OTD estimation enhancement, and transmit identical reference signals from the plurality of base station transmitters, the reference signals being identical both in the signal sequence and time-frequency resources used for transmission.

Methods and apparatuses, through the use of a Downlink Control Indication (DCI) format or through higher layer signaling, for dynamic activation and deactivation of Sounding Reference Signal (SRS) transmissions from User Equipments (UEs) in an UL Component Carrier (CC) with configured SRS transmissions, the dynamic configuration of SRS transmissions parameters, the dynamic activation and configuration of SRS transmissions in an UL CC without previously configured SRS transmissions for a reference UE, and the configuration of SRS transmissions from multiple UE transmitter antennas.

A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

A system and method for initializing a system communication without previous reservations for random access channel (RACH) access includes a first step of defining at least one spread sequence derived from at least one constant amplitude zero autocorrelation sequence. A next step includes combining the spread sequence with a Walsh code to form an extended spread sequence. A next step includes using the extended spread sequence in a preamble for a RACH. A next step includes sending the preamble to a BTS for acquisition. A next step includes monitoring for a positive acquisition indicator from the BTS. A next step includes scheduling the sending of a RACH message. A next step includes sending the RACH message.

Methods and systems are provided for use with wireless networks having once or more cell in which each cell includes a base station (BS), at least one relay station (RS) and at least one mobile station (MS). The at least one relay station can be used as an intermediate station for providing communication between the BS and MS. Methods are provided for an RS to initially access the network, access of the RS by MSs initially accessing the network, methods of allocating OFDM resources for communicating between the BS, RS and/or MS for example dividing transmission resources into uplink and downlink transmissions, and methods of inserting pilot symbols into transmission resources used by the RS. In some embodiments on the invention, the methods are consistent and/or can be used in conjunction with existing standards such as 802.16e.

Communication is provided which includes receiving a transmitted radio signal at a powerline wherein the powerline functions as a receiving antenna for the wirelessly transmitted radio signal. The powerline is coupled to an input of a radio receiver using a coupler to communicate the radio signal to the radio receiver. For calibration purposes a second antenna not coupled to powerline may be used. A method for powerline communication across transformers, open circuit breakers, and other devices is also provided. In addition, a method of monitoring a device connected to a powerline is provided.

A method is provided for communicating signals at a low power level in an electromagnetic interference (EMI) environment. A first device transmits a modulated signal having a first carrier frequency, including the encoded information via a hardwire transmission medium. In one aspect, the power level of the modulated signal can be adjusted to minimize power consumption or reduce the generation of EMI. The modulated signal may be in one of the following formats: frequency modulation (FM) or phase modulation (PM) to name a few examples. A second device including a logarithmic detector amplifier (LDA) demodulator circuit receives the signal, which may be mixed with EMI. The LDA demodulator circuit amplifies the modulated signal, without amplifying the EMI, to supply a demodulated baseband signal, which may be an n-ary digital signal, or an audio signal. A low-power, noise insensitive communication channel is also provided.

A method and apparatus provides OFDM signal compression for transfer over serial data links in a base transceiver system (BTS) of a wireless communication network. For the uplink, an RF unit of the BTS applies OFDM cyclic prefix removal and OFDM frequency transformation of the baseband signal samples followed by frequency domain compression of the baseband signal samples, resulting from analog to digital conversion of received analog signals followed by digital downconversion, forming compressed coefficients. After transfer over the serial data link, the baseband processor applies frequency domain decompression to the compressed coefficients prior to further signal processing. For the downlink, the RF unit performs frequency domain decompression of the compressed coefficients and applies OFDM inverse frequency transformation of the decompressed coefficients and OFDM cyclic prefix insertion prior to digital upconversion and digital to analog conversion, generating the analog signal for transmission over the antenna.

In a method for transmitting a contention free scheduling request in a cellular network, a set of N frequency opportunities is defined within a scheduling request slot. A set of R CAZAC root sequences is then defined per frequency opportunity. A set of C cyclic shifts is then defined per CAZAC root sequence. Within a given cell, a unique identification number is assigned to each user equipment (UE) that is in an uplink (UL) synchronized state. Each UL synchronized UE is mapped to a unique combination of one of the N frequency opportunities, one of the R CAZAC root sequences and one of the C cyclic shifts. A cyclic shifted preamble sequence for a given UE is transmitted as a scheduling request on the mapped frequency, CAZAC root sequence and cyclic shift opportunity, wherein the unique identification number of the given UE is encoded by the combination of the frequency opportunity, CAZAC root sequence opportunity, and amount of cyclic shift, such that up to all of the plurality of UE can transmit a schedule request (SR) in a non-contentious manner in one schedule request slot.

A calibration method according to the present invention includes a step of first channel estimating for transmitting a pilot signal from a first antenna and receiving the pilot signal at a second antenna different from the first antenna to calculate a first channel estimation value; a step of second channel estimating for transmitting a plot signal from the second antenna and receiving the pilot signal at the first antenna to calculate a second channel estimation value; and a step of correction coefficient calculating for calculating, by using the first and second channel estimation values, a correction coefficient.

A method and apparatus for transmitting control information is provided for use in detection of interference an signal in a wireless communication system. An interference control method of a base station of a mobile communication system includes scheduling data to be transmitted to a terminal and transmitting control information including data channel information on the scheduled data and interference signal information to the terminal.

In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response.

For an incremental redundancy (IR) transmission in a MIMO system, a transmitter processes (e.g., encodes, partitions, interleaves, and modulates) a data packet based on a selected rate to obtain multiple data symbol blocks. The transmitter transmits one data symbol block at a time until a receiver correctly recovers the data packet or all blocks are transmitted. Whenever a data symbol block is received from the transmitter, the receiver detects a received symbol block to obtain a detected symbol block, processes (e.g., demodulates, deinterleaves, re-assembles, and decodes) all detected symbol blocks obtained for the data packet, and provides a decoded packet. If the decoded packet is in error, then the receiver repeats the processing when another data symbol block is received for the data packet. The receiver may also perform iterative detection and decoding on the received symbol blocks for the data packet multiple times to obtain the decoded packet.

Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Generated estimates and/or approximations can be used in evaluating system performance and directly or indirectly dictating/requiring changes or recommending improvements in operation by transmitters and/or other parts of the communication system. Data and/or other information may be collected using “internal” means or may be obtained from system elements and components via email and/or other “external” means. The likelihood of a model's accuracy can be based on various data, information and/or indicators of system performance, such as observed normal operational data, test data and/or prompted operational data that shows operating performance based on stimulation signals. One example of such prompted data uses frequency carrier masks to approximate the Hlog of a given channel, including information regarding bridged taps, attenuation, etc.

A signal detector employs a coherent accumulation system that coherently combines the correlation results derived from segments of samples of a received signal. The segments may have non-uniform lengths and may have been obtained over different and non-overlapping time periods. The segments are obtained during sampling windows of arbitrary length and at arbitrary times, and the results of processing the segments are successively combined in a coherent manner (separate magnitude and phase accumulation) until a threshold signal-to-noise ratio (SNR) has been achieved. Coherent integration is enabled by introducing a carrier phase offset as well as a code phase offset, so that different segments are aligned in carrier phase as well as code phase. Although not limited to this application, in one implementation example, the signal detector is used in connection with and as part of a global positioning system (GPS) receiver.

Disclosed is a method, a computer program product and a device that includes a receiver for receiving a downlink signal transmitted into a cell. The receiver is operable to obtain time, carrier frequency and cell-specific preamble synchronization to the received signal and includes a plurality of synchronization units that include a first detector to detect a frame boundary using preamble delay correlation; a second detector to detect the frame boundary with greater precision using a conjugate symmetry property over a region identified by the first detector; a cyclic prefix correlator to resolve symbol boundary repetition; an estimator, using the cyclic prefix, to estimate and correct a fractional carrier frequency offset; an operator to perform a Fast Fourier Transform of an identified preamble symbol and a frequency domain cross-correlator to identify cell-specific preamble sequences and an integer frequency offset in sub-carrier spacing. The transmitted signal may be a downlink signal transmitted into the cell from a base station that is compatible with IEEE 802.16e (WiMAX).

A method and apparatus of transmitting a reference signal in a wireless communication system is provided. The method includes generating a precoded reference signal or a non-precoded reference signal in accordance with a rank, and transmitting the generated reference signal. Uplink transmission using multiple transmit antennas is supported through reference signal design and related control signaling.

The present invention provides a receiver. In one embodiment, the receiver includes a receive portion employing transmission signals from a transmitter having multiple antennas and capable of providing channel estimates. The receiver also includes a feedback generator portion configured to provide to the transmitter a pre-coder selection for data transmission that is based on the channel estimates, wherein the pre-coder selection corresponds to a grouping of frequency-domain resource blocks. The present invention also provides a transmitter having multiple antennas. In one embodiment, the transmitter includes a transmit portion coupled to the multiple antennas and capable of applying pre-coding to a data transmission for a receiver. The transmitter also includes a feedback decoding portion configured to decode a pre-coder selection for the data transmission that is fed back from the receiver, wherein the pre-coder selection corresponds to a grouping of frequency-domain resource blocks.

A system and method for canceling interference present in a code-division multiple access (CDMA) channel signal received at a CDMA receiver that is caused by multipath components of a transmitted pilot channel signal or by soft handoff conditions is computationally efficient because it operates at symbol rates. The channel signal from which such multipath interference is canceled can be either a traffic (data) channel or the pilot channel itself. Interference signals are produced in groups corresponding to the fingers of the CDMA rake receiver. The interference signals corresponding to each finger are used to cancel interference in the other fingers.

Disclosed is a method for uplink scheduling in a communication system. The method for uplink scheduling in a communication system having a cellular structure hopping between sub-channels according to a predetermined rule whenever a signal is transmitted The communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands. The method includes determining a number of sub-channels to be allocated to a mobile station such that throughput of the mobile station is maximized based on a first predetermined condition in which a mobile station having a superior channel state is allocated with a greater number of sub-channels than a mobile station having an inferior channel state, and determining a modulation and coding scheme level according to a signal-to-interference and noise ratio (SINR) of a downlink channel reported by the mobile station based on a second predetermined condition capable of improving a channel state of the mobile station having an inferior channel state.

In bus communications methods and apparatus, a first set of physical signals representing the information to be conveyed over the bus is provided, and mapped to a codeword of a spherical code, wherein a codeword is representable as a vector of a plurality of components and the bus uses at least as many signal lines as components of the vector that are used, mapping the codeword to a second set of physical signals, wherein components of the second set of physical signals can have values from a set of component values having at least three distinct values for at least one component, and providing the second set of physical signals for transmission over the data bus in a physical form.

Radio communication apparatus for receiving OFDM signal from base station and transmitting FH signal to base station, using sub-channels, base station comparing hopping pattern information items indicating hopping patterns from radio communication apparatuses including radio communication apparatus, and generating collision information when hopping patterns include colliding hopping patterns, includes estimation unit configured to estimate channel response values of sub-channels based on OFDM signal, selector which selects, from sub-channels, several sub-channels which have higher channel response values than a value, each of channel response values being expressed by power level, signal-to-noise power ratio, or signal-to-interference ratio, determination unit configured to determine hopping pattern from selected sub-channels, transmitter which transmits, to base station, hopping pattern information item indicating determined hopping pattern, receiver which receives collision information from base station, and correction unit configured to correct hopping pattern based on collision information.

Methods and apparatus for generating and processing a signal are disclosed. The signal may comprise a plurality of mutually orthogonal subcarriers constituting a plurality of bands. The signal may be either an optical or a radio frequency signal.

A method includes separating resource elements from multiple code blocks into different groups, and decoding the code bits of the resource elements within each group without waiting for a completed reception of a transport block to start decoding.

A method includes separating coded bits from multiple code blocks into different groups, and decoding the code blocks containing coded bits within each group. A first CRC is attached to the transport block and a second CRC is attached to at least one code block from the transport block.

An improved channel interleaver design method including mapping from coded bits of different code blocks to modulation symbols, and mapping from modulation symbols to time, frequency, and spatial resources, to make sure each code block to get roughly the same level of protection.