7197 results about "Transmission channel" patented technology

A method of determining a channel estimate of a first transmission channel in a communications system. The method comprises deriving a first set of channel estimates from symbols received through said first transmission channel; deriving a second set of channel estimates from symbols received through a second transmission channel in the communications system; determining a scale factor between the first and second sets of channel estimates from a least squares error criterion; and determining the channel estimate of the first transmission channel as a channel estimate of the second transmission channel scaled by the determined scale factor.

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.

Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a “beam-forming” transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a “multi-mode” transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment.

A method and a device for the coding and decoding of an information symbol for transmission over a transmission channel or a received signal value is described and illustrated, whereby a channel symbol used for coding is selected from at least two available channel symbols by means of a pre-calculated expected received signal value. The pre-calculation is achieved, based on the echo properties of the transmission channel and transmission values already sent. A pre-coding method with low receiver-side calculation requirement is thus prepared, whereby the information symbol can be transmitted by means of various channel symbols and thus various transmission values can also be transmitted. The possible selections may be used for minimization of the transmission energy and / or to achieve a minimal disturbance or even a constructive effect through the inter-symbol interference occurring on transmission.

Closed loop wireless communication of signals using an adaptive transmit antenna array (3), in which a plurality of copies of signals to be transmitted by the transmit antenna array (3) are produced with delays and weights (wnj) that are functions of the multi-path transmission channel characteristics (H) from the transmit antenna array (3) to a receive antenna array (4) of a receiver (2) and are combined before transmission by the transmit antenna array. The delays and weights (wnj) of the transmit copies for each transmit antenna element are functions of the respective multi-path transmission channel characteristics (hn,m=1l=1,…⁢ ,hn,m=Ml=L)from that transmit antenna element to the receive antenna array (4) ssuch that the multi-path signal components propagated to each receiver element are received with distinguishable delays according to the propagation path. The receiver (2) combines the received signal components from each receive antenna element with delays and weights (u) that are respective functions of the multi-path transmission channels. Preferably, the receiver comprises a multi-finger RAKE receiver (6) that copies the received signals from the receive antenna array with delays and weights (u) that are respective functions of the multi-path transmission channels and combines the copied received signals.

A technique for allocating bandwidth in a digital broadband delivery system (DBDS) using a bandwidth allocation manager to dynamically assign a content delivery mode to a plurality of digital transmission channels based on an allocation criteria received from a subscriber is disclosed herein. The bandwidth allocation manager determines a bandwidth allocation schedule for a predetermined bandwidth based on allocation criteria comprising a criteria received from a subscriber. The allocation criteria received from the subscriber may comprise a subscriber reservation request which is processed by the bandwidth allocation manager to determine the bandwidth allocation schedule.

System and method for decentralized control of wireless networks, made up by a set of access points (AP) that provide connection service to a set of stations (STA). The method comprises carrying out, during the start-up process, an automatic selection of the transmission channel (S7) of each access point (AP) to minimize interference, and which is based on the following information transmitted between the access points (AP) in the network:a list of the access points (AP) that are within the range of reach of each access point (AP) in the network;the powers with which each access point (AP) receives signals from the access points within its reach;a list of preferred channels, with the lowest level of interference, for each access point (AP) in the network.The method also enables, among other features, carrying out an automatic transmit power selection (S8).

A Digital Home Communication Terminal (DHCT) including a plurality of tuners, each of which can select one of a plurality of transmission channels provided by a Digital Broadband Delivery System (DBDS). The multiple tuners enable the DHCT to tune to a plurality of downstream media and data transmissions, thereby allowing a subscriber to tune simultaneously to multiple channels and content transmitted in the downstream transmission via the DBDS, an advantage over conventional DHCTs. The present invention enables subscribers to receive and view multiple channels and associated content, including electronic program guide information, at will. Furthermore, using the multiple-tuner DHCT of the present invention, subscribers can view multiple television stations and program content simultaneously, without degradation to television signals or pictures.

a radio communication system which includes a base station apparatus and terminal apparatuses and performs TDD two-way communications using an OFDM signal including subcarriers in a downstream communication from the base station apparatus to each terminal apparatus, and an FH signal having the same frequency band as that of the subcarriers in an upstream communication from the each terminal apparatus to the base station apparatus, the each terminal apparatus estimates transmission channel characteristics of the subcarriers based on the OFDM signal received, transmits an estimation result of the estimation unit to the base station apparatus, and the base station apparatus assigns, to the each terminal apparatus, at least one of subcarriers to be used in the downstream communication of the subcarriers and a hopping pattern to be used in the upstream communication, based on the estimation result transmitted from the each terminal apparatus.

The present invention provides a method and system for estimating common amplitude and phase errors of a multiple channel wireless system. The multiple channel wireless system includes a plurality of transmission channels formed between a plurality of transmission antennas and a plurality of receiver antennas. The method includes estimating transmission channel elements between each transmission antenna and receiver antenna pair of the multiple channel wireless system. Calibration symbols are transmitted from each transmit antenna. Signals are received that correspond to the calibration symbols having traveled through the transmission channels. Received calibration symbols are estimated based upon spatial processing of the received signals and the estimated transmission channel elements. Common amplitude and phase errors are estimated for each transmit and receive antenna pair by comparing the transmitted calibration symbols with the received calibration symbols.

When an advertisement break is detected on a program channel stream, demographic data is obtained which is descriptive of the subscribers who are currently watching material from the program channel stream, and one or more streams containing substitute advertisements are generated based on the demographic data. The substitute advertisements in each stream, thus generated, are targeted at a different demographic group of the subscribers. The number of substitute advertisement streams corresponds to the number of unused transmission channels allocated for transmission of such streams. Groups of subscribers' set-top terminals (STTs) are directed to tune to the allocated transmission channels during the advertisement break to receive the substitute advertisement streams, respectively. Consequently, the subscribers are shown the substitute, targeted advertisements instead of the regularly-scheduled advertisements.

A technique for monitoring optical power in a fiber array unit having a plurality of optical transmission waveguides terminating at an edge thereof for carrying optical signals to and / or from a PLC. A tapping filter is placed within a slit formed in the substrate and interrupting the transmission channels, thereby tapping at least some of the optical power from the channels and directing the tapped optical power toward respective photodetector channels for detection, while allowing other optical power to continue transmission in the at least one channel of the fiber array unit.

A system and method is provided for coordinating wireless bandwidth usage of a common frequency band by wireless nodes in two disjoint networks, such as an infrastructure (“IS”) network and an ad hoc (“AH”) network. When AH nodes move into the transmission range of an access point of the IS network, they register with the access point and listen to the access point to tell them when they are allowed to transmit data over a given transmission channel. The access point coordinates the bandwidth usage by broadcasting ad hoc mode poll signals to indicate that the ad hoc nodes may transmit over the channel, and sending infrastructure mode poll signals to indicate that a wireless node in the IS network can transmit over the given channel. The access point makes a fraction of the bandwidth available for communications by the wireless AH nodes in its transmission range, while guaranteeing the rest of the bandwidth for wireless nodes in the IS network.

An optical data link includes first and second pluralities of transmission devices, at least one of which is configured as an array. A multichannel transmission link has a first end connected to the first plurality of transmission devices and a second end connected to the second plurality of transmission devices so as to form a plurality of parallel transmission channels therebetween. The multichannel transmission link includes a multicore fiber with a plurality of individual cores having a configuration matching the array configuration of the at least one plurality of transmission devices. The multicore fiber has an endface connected directly to the at least one plurality of transmission devices, with the individual cores of the multicore fiber aligned with respective devices in the at least one plurality of transmission devices. Further described are access networks and core networks incorporating a transmission link comprising at least one span of a multicore fiber.

The invention discloses a density evolution based polarization code constructing method and polarization code coding and decoding system. According to the invention, the code length N and the information bit length K of an information code to be processed are obtained, an expectation value set of a log-likelihood ratio probability density function of N bit channels, K bit channels are selected as the information bit channels according to the expectation value set and information bit information index vector quantity is generated; an information bit sequence and a fixed bit sequence are mixed and the mixed bit vector quantity is multiplied by a polarization code for generating a matrix so as to output an encoding sequence; the encoding sequence is modulated and input into a transmission channel and the sequence output by the transmission channel is subjected to decoding operation by adopting a polarization code decoding algorithm, bit error probability and frame error rate of the decoded code are calculated and a design signal to noise ratio is changed, the above operation is repeated until the bit error probability and frame error rate become the minimum. The method and system provided by the invention are suitable for general binary system memoryless channels, the bit error probability and frame error rate are low, the calculation complexity is low and the communication performance of a communication system is improved.

The present invention provides a method for transmission of a images and / or video over bandwidth limited transmission channels having varying available bandwidth, which method comprises the use of a classification algorithm for decomposing the images and / or video to be transmitted into multiple spatial areas, each area having a specific image type; detecting the image type of each of those areas separately selecting for each of those areas an image and / or video encoding algorithm having a compression ratio. The classification algorithm prioritizes each of the areas, the classification algorithm increasing the compression ratio of the image and / or video encoding algorithm dedicated to spatial areas having lower priority in case of decreasing bandwidth.

The invention pertains to transmission to a remote station, by means of transmission channels (generally radio transmission channels), of seismic data acquired by a data collection equipment comprising a plurality of acquisition units, each being suited to acquire, to store and preferably to compress the data to be transmitted. The invention comprises ordered storage, in a high-capacity memory (flash type memory for example) of each acquisition unit (Ai), of data obtained during successive emission-reception cycles (acquired and possibly preprocessed seismic data) so as to form a stream of stored data to be transmitted, and progressive transfer of the stored data stream from each acquisition unit to the remote station by means of the transmission channel, by reading each storage memory, with a time lag in relation to the time of their storage depending on the transmission rate of each transmission channel and on the transmission mode selected with preferably, if sending of the data of a cycle is delayed, sending of at least partial data, compressed or not, for quality control purposes. The data transmitted are reconstituted at the remote station. The method can be used for large-scale seismic data transmission.

Object recognition apparatus and methods useful for extracting information from an input signal. In one embodiment, the input signal is representative of an element of an image, and the extracted information is encoded into patterns of pulses. The patterns of pulses are directed via transmission channels to a plurality of detector nodes configured to generate an output pulse upon detecting an object of interest. Upon detecting a particular object, a given detector node elevates its sensitivity to that particular object when processing subsequent inputs. In one implementation, one or more of the detector nodes are also configured to prevent adjacent detector nodes from generating detection signals in response to the same object representation. The object recognition apparatus modulates properties of the transmission channels by promoting contributions from channels carrying information used in object recognition.

The invention provides an LTE and WLAN interconnecting system and a switching method; and the system introduces the entity of a virtual base station under an LTE architecture, and accesses the entity into the interface of the LTE as WLAN. On the LTE side, the virtual base station remains transparent relative to the LTE side, and is provided with the functions of a general LTE base station. On the WLAN side, the virtual base station can control the WLAN access point. The switching between the LTE and the WLAN is realized through the virtual base station through a standard X2 interface. A second layer tunneling protocol or an Ethernet tunneling protocol is adopted between the virtual base station and the WLAN access point to realize the transmission and the receiving of data and signaling during the switching process, and the WLAN serves as the bottom layered transmission channel of the data and the signaling of an LTE system. The method has the advantage that for the LTE, the switching process is kept consistent with the LTE switching process, which has very small impact on the traditional LTE. The WLAN is connected with the LTE in a tight coupling way, thereby greatly meeting the business requirement requirements, reducing the time delay caused by system switching, and ensuring the system performance.

Systems and methods for dynamically allocating bandwidth in a digital broadband delivery system are disclosed. One example method includes receiving information describing subscriber requests for content delivery, receiving bandwidth allocation criteria, and processing the information describing subscriber requests and the bandwidth allocation criteria according to a statistical model. The bandwidth allocation criteria comprise at least one of subscriber pricing information, content delivery mode information, and program content information. The processing produces a bandwidth allocation schedule in which one of a plurality of content delivery modes is assigned to each of a plurality of digital transmission channels for each of a plurality of time periods.

In a closed-loop wireless communication system, a codebook-based precoding feedback compression mechanism is provided to remove redundancy from the precoding feedback that is caused by channel correlation in time and frequency. Redundancy due to temporal correlation of the transmission channel is removed by sending precoding feedback only if there is a change in the precoder state for the channel to the receiver. Redundancy due to frequency correlation is removed by run length encoding the precoding feedback, thereby compressing the precoding feedback prior in the frequency domain. By compressing the precoding feedback, the average rate of precoder feedback is reduced.

The present invention selects a space-time encoding mode to use when transmitting with spatial diversity based on the receive diversity associated with a receiver device and the quality of the transmission channels based on information fed back from the receiver device. The selectable space-time encoding modes are preferably space-time transmit diversity encoding and a version of BLAST-type encoding. Further, modulation modes, error encoding rates, or a combination thereof, may also be based on the quality of the transmission channels and the available diversity of the receiver device.

An apparatus for producing a fingerprint signal from an audio signal includes a means for calculating energy values for frequency bands of segments of the audio signal which are successive in time, so as to obtain, from the audio signal, a sequence of vectors of energy values, a means for scaling the energy values to obtain a sequence of scaled vectors, and a means for temporal filtering of the sequence of scaled vectors to obtain a filtered sequence which represents the fingerprint, or from which the fingerprint may be derived. Thus, a fingerprint is produced which is robust against disturbances due to problems associated with coding or with transmission channels, and which is especially suited for mobile radio applications.

A method for reducing self-interference between at least four data symbols that are modulated via a non-orthogonal matrix modulation and transmitted from at least four transmit antennas to at least one receive antenna comprises mapping the at least four data symbols onto the at least four transmit antennas and two orthogonal transmission resources via the non-orthogonal matrix modulation, multiplying data symbols mapped to one of the at least four transmit antennas with a factor γ, wherein γ is determined at least in dependence on the transmission channel characteristics from the at least four transmit antennas to the at least one receive antenna to reduce a self-interference between the at least four data symbols, and transmitting the mapped data symbols and the mapped and multiplied data symbols from the at least four transmit antennas to at least one receive antenna in the two orthogonal transmission resources.

A wireless base station device includes a wireless unit for performing wireless communications with a mobile station; a reception memory unit for storing therein reception spectrum spread data as reception data; a baseband reception unit for processing and decoding the reception data stored in the reception memory unit; a common downlink channel reception unit for receiving a downlink signal of other base station devices; a frame protocol processing unit for converting a transmission channel format; a baseband transmission unit for outputting encoded data; a spread processing unit for outputting spread-modulated data to the wireless unit; and a call controller for controlling an allocation of processing resources. Parameters including a spreading code and a transmission power required for installing the wireless base station device are automatically set by operating the common downlink channel reception unit to detect notification information and signal levels of neighboring base station devices.

A method for establishing wireless communication between a transmitter and a receiver in a wireless communication system. The receiver includes an adaptive array that has at least two antennas. Each antenna receives a signal and produces a received signal. The transmitter includes at least two transmission channels for communicating the signal from the transmitter to the receiver. The wireless communication system suppresses interference at the receiver by applying an interference suppression technique when combining the received signals. The selection of a channel at the transmitter is based on the channel performance at the receiver for each transmission channel. The channel performance is based on a combining technique different from the interference suppression technique.