807 results about "Channel correlation" patented technology

The disclosed invention is referred to a method for optimising the random access procedures in third generation CDMA cellular telephony systems. The particular embodiment of the example concerns a TD-SCDMA-TDD synchronous realization. The disclosed procedure includes a preliminary part charged to the network (BSSC, MSC) only for establishing the following associations between the configuration parameters of the involved physical channels: one signature burst (SYNC1) is associated to one forward access channel (P-FACH) only, in order to avoid any, ambiguity in the mobile stations about where to look for the expected acknowledgement from the network; one random access common channel (P-RACH) is associated to one forward access channel (P-FACH) only, in order to reduce collision on the latter (P-RACH); one access grant channel (P / S-CCPCH, AGCH) only is associated to one random access common channel (P-RACH), in order to avoid any ambiguity in the mobile stations about where to look for the expected answer from the network with the indication of the dedicated service channels (DPCH); and each complete associative link binding the involved physical channels is included in the system information and broadcasted into the serving cell to be read by the mobile stations (MS, UE) when entering an actual part of the procedure charged to exchange protocol messages with the network (BSSC, MSC) through said associative links that being signalling at once to the mobile stations the route towards the services offered by the network, simplifying the access procedure consequently. Suitable groupings among: Downlink pilot sequences, Uplink pilot sequences, scrambling codes, basic midambles, are carried out in a cell-discriminating way and broadcasted into the cell to simplify the serving cell selection procedure (<cross-reference target="DRAWINGS">FIG. 1< / cross-reference>).

A scheme for stereo and multi-channel synthesis of inter-channel correlation (ICC) (normalized cross-correlation) cues for parametric stereo and multi-channel coding. The scheme synthesizes ICC cues such that they approximate those of the original. For that purpose, diffuse audio channels are generated and mixed with the transmitted combined (e.g., sum) signal(s). The diffuse audio channels are preferably generated using relatively long filters with exponentially decaying Gaussian impulse responses. Such impulse responses generate diffuse sound similar to late reverberation. An alternative implementation for reduced computational complexity is proposed, where inter-channel level difference (ICLD), inter-channel time difference (ICTD), and ICC synthesis are all carried out in the domain of a single short-time Fourier transform (STFT), including the filtering for diffuse sound generation.

A method and apparatus are provided for providing an acknowledgement (ACK) message combined with one or more communication message of a data packet that is transmitted using a single channel. The method comprising acts of associating the ACK with a channel ID of a recipient; building the ACK information data pattern, wherein the length of the ACK message is based on number of ACK messages to be transmitted; and combining the ACK information data pattern with one or more communication message by applying an encoding scheme over the combined message.

Sending channel related parameters known as channel state information (CSI) over a WLAN return channel. The size of these coefficients is not fixed. Rather, the coefficients are quantized in a certain resolution, which is determined adaptively according to a measure of the channel quality. This allows minimizing the component of the bandwidth of the wireless connection that is not used for payload transfer.

A communication system includes a shared channel occupied by a plurality of user equipments (UEs) and spread with a plurality of channelization codes to transmit user data, and a plurality of control channels for transmitting control information related to the shared channel in order to enable the UEs to receive the shared channel signal. The system generates a plurality of control channel sets by classifying the control channels into a predetermined number of control channels, and assigns the control channel sets so that each of the UEs monitors a particular control channel set among the control channel sets. Upon detecting necessity to modify a control channel set to be assigned to a particular UE among the UEs, a Node B determines to modify a control channel set assigned into the UE to a new control channel set at a predetermined point of time to come. After determining to modify the control channel set, the Node B transmits an indicator indicating expected modification of the control channel set and information on the control channel set to be modified to the UE over a downlink.

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.

Network bandwidth detection and distribution and prioritizing network traffic among two or more distinct channels of communication within a single application in a node configured to communicate with one or more other nodes over a network is disclosed. For a particular time quantum, a bandwidth quantum may be distributed amongst two or more communication channels according to priorities associated with those channels.

The present invention provides a method of interference mitigation in a wireless communication system. The method that may include reducing transmission power associated with at least one first channel provided by at least one first base station associated with at least one corresponding first coverage area adjacent a second coverage area associated with a second base station concurrently with maintaining at least one transmission power associated with the second base station(s). The method may also include increasing the transmission power associated with the first channel(s) provided by the first base station(s) concurrently with reducing at least one transmission power associated with at least one first channel provided by the second base station(s).

The present invention provides a method for implementation in a first functional entity in a wireless communication system that includes a first plurality of base stations for providing wireless connectivity to at least one mobile unit. In one embodiment of the method includes receiving, at the first functional entity, channel state information associated with a plurality of wireless communication channels between the first plurality of base stations and the mobile unit. Selection of a second plurality of base stations from the first plurality of base stations is performed jointly with resource allocation to the second plurality of base stations using the channel state information. The first functional entity then communicates information indicative of the selected second plurality of base stations and the allocated resources to the selected second plurality of base stations.

A signal filtering system and method that may be used in conjunction with a repeater or an input stage of a base-station. The system may include an analog to digital converter adapted to sample a received signal and to produce a data stream corresponding to the received signal in the time domain, a filtering block having one or more digital filter elements, wherein each of said one or more filter elements is adapted to filter one or more sets of frequency bands associated with one or more communication channel, and a controller adapted to configure said one or more digital filter elements based on parameters stored on a database and / or based on parameters received via a modem.

A communication infrastructure for a data processing apparatus, and a method of operation of such a communication infrastructure are provided. The communication infrastructure provides first and second switching circuits interconnected via a bidirectional link. Both of the switching circuits employ a multi-channel communication protocol, such that for each transaction a communication path is established from an initiating master interface to a target slave interface, with that communication path comprising m channels. The m channels comprise one or more forward channels from the initiating master interface to the target slave interface and one or more reverse channels from the target slave interface to the initiating master interface, and handshaking signals are associated with each of the m channels. The bidirectional link comprises n connection lines, where n is less than m, the bidirectional link supporting a first communication path from the first switching circuit to the second switching circuit and a second communication path in an opposite direction from the second switching circuit to the first switching circuit. Control circuitry is used to multiplex at least one forward channel of the first communication path and at least one reverse channel of the second communication path, with the multiplexing being performed in dependence on the handshaking signals associated with the channels to be multiplexed. This allows the 2m channels formed by the first and second communication paths to be provided by the n connection lines of the bidirectional link.

A system and method for synchronous spectrum sharing for a dedicated network in a wireless communication system based on orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) signaling is disclosed. The system and method includes detecting a frame of a broadcast waveform and extracting idle spectrum information associated with the dedicated subchannel to the secondary user node. The system allows transmitting data from the secondary user node in unused symbol slots identified in the idle spectrum information thereby making efficient use of unused or idle spectrum. Accordingly, secondary users of the wireless communication system can dynamically form ad-hoc mesh network communications in fixed or mobile scenarios.

The present invention is directed to a frequency hopping spread spectrum transceiver. The transceiver includes a microcontroller; a transmitter having a voltage controlled oscillator, a direct digital synthesizer, and a power amplifier; and a receiver having an amplifier, a mixer, an IF amplifier, a demodulator, and a data slicer. When transmitting, the transmitter communicates a preamble over a predetermined number of preamble channels, and thereafter communicate groups of data bytes that each comprise a subset of the data message over a predetermined sequence of data channels. When receiving, the receiver investigates the predetermined number of preamble channels to search for the preamble, each of the predetermined number of preamble channels being associated with a predetermined number of data channels in each sequence of data channels. A number of bytes that comprises each group of data bytes is determined in accordance with a number of channels in the sequence of data channels and the predetermined number of times each byte of the data message is to be transmitted.

A scheme for stereo and multi-channel synthesis of inter-channel correlation (ICC) (normalized cross-correlation) cues for parametric stereo and multi-channel coding. The scheme synthesizes ICC cues such that they approximate those of the original. For that purpose, diffuse audio channels are generated and mixed with the transmitted combined (e.g., sum) signal(s). The diffuse audio channels are preferably generated using relatively long filters with exponentially decaying Gaussian impulse responses. Such impulse responses generate diffuse sound similar to late reverberation. An alternative implementation for reduced computational complexity is proposed, where inter-channel level difference (ICLD), inter-channel time difference (ICTD), and ICC synthesis are all carried out in the domain of a single short-time Fourier transform (STFT), including the filtering for diffuse sound generation.

A method of reverse link power control for a reverse packet data channel in a wireless communication system allows a mobile station to autonomously change its data transmission rate. The mobile station transmits packet data over a reverse packet data channel having a data rate variant transmit power level that varies based on a transmit data rate on the packet data channel. The mobile station further transmits control signals over a reverse control channel associated with the reverse packet data channel. The transmit power level of the reverse control channel is such that the transmit power level does not vary with the transmit data rate on the packet data channel. The radio base station measures the strength of the received signals on the reverse control channel, compares the measured strength to a power control set point, and generates a power control signal responsive to the comparison of the control signal to the power control set point.

A differential magnetic field sensor that enables operation that is independent of sensor-to-target orientation is presented. The differential magnetic field sensor is provided with at least two differential channels. Each differential channel includes a pair of magnetic field sensing elements and has a respective sensing axis defined by those magnetic field sensing elements. The sensing axes are not aligned with respect to each other. One sensing axis is positioned relative to a reference axis of a target profile to define an orientation angle between the sensing axis and the reference axis. The differential magnetic field sensor includes circuitry to produce differential signals associated with the differential channels and use those differential signals to produce a single differential signal having an amplitude that is independent of the orientation angle.

A diversity receiver includes a first receiving channel and a second receiving channel. The receiver also includes a baseband processor that computes a difference between the received signal strengths of the signals received from the first and second channels, wherein the processor disables the signal received from the second channel if the difference is greater than a first threshold value and a BER associated with the second receiving channel is greater than a BER threshold value, and disables the signal received from the first channel if the difference is less than the negative first threshold value and the bit error rate (BER) associated with the first channel is greater than the BER threshold value. The receiver further includes a bypass circuit coupled to an input of an amplifier and a RSSI circuit that provides a conduction path between the input and a ground when the RSSI circuit detects a blocker signal.

The invention provides a method for acquiring information of a downlink channel, comprising the following steps: a terminal sends a detection pilot frequency and downlink interference information to abase station; the base station acquires uplink channel status information according to the detection pilot frequency so as to acquire equivalent downlink channel status information, and acquires downlink channel relevant information according to equivalent downlink channel status information and downlink interference information. The invention provides a system for acquiring downlink channel information, and also provides a method for acquiring uplink channel information. The method comprises the following steps: the base station sends the uplink interference channel status information and adownlink pilot frequency to the terminal; the terminal acquires downlink channel status information according to the downlink pilot frequency so as to acquire equivalent uplink channel status information, acquires uplink channel relevant information according to the equivalent uplink channel status information and uplink interference information, and sends the acquired uplink channel quality information to the base station. The invention also provides a system for acquiring the uplink channel information, and acquires channel information by utilizing channel reciprocity, thus reducing uplink expenditure.

Methods and Systems are provided for bridging heterogeneous media packets using a single processor resource having a virtual bridge. Network interfaces associated with heterogeneous media channels relay network packets to the virtual bridge. The virtual bridge accesses metadata associated with the relayed network packets and translates the network packets to between media formats. The translated network packets are then relayed to an appropriate network interface. In one embodiment, the virtual bridge is dynamically configurable within the processing resource.

A system and methodology are disclosed for exploiting channel correlation in time and / or frequency to reduce CQI feedback in wireless communications systems. By compressing CQI feedback at the receiver to reduce redundancy in CQI feedback information that results from the channel correlation, the average feedback rate is reduced. In various embodiments, redundancy in time may be removed from the CQI feedback by monitoring variations of the CQI information in time at the receiver so that CQI information for a given CQI reporting instance is communicated to the transmitter only if it differs from the CQI information for the previous CQI reporting instance. Otherwise, no feedback is performed. In other embodiments, CQI feedback is compressed by performing a discrete cosine transform (DCT) on the CQI data. The compressed CQI feedback information is then communicated to the transmitter through the feedback control channel where it is decoded into the original CQI information and used to generate signal processing information for various sub-carriers.

A method of requesting a communication resource by a wireless communication unit operating in a wireless communication system. The wireless communication system provides for uplink and downlink channels. The method includes the steps of: allocating a dedicated communication channel to said wireless communication unit by a wireless communication serving unit; transmitting a communication resource request message (130) on said dedicated uplink channel by said wireless communication unit (110) to said wireless communication serving unit (120); and transmitting an access allocation message (140) to said wireless communication unit (110) from said wireless communication serving unit (120) on said dedicated downlink channel. A communication system and communication unit are also provided. This provides the advantage that a dedicated channel is used for requesting shared resources thereby avoiding various problems, including clashes, associated with using a random access channel.

A base station transmits blocks, in successive transmission time intervals, to radio terminals, over communication channels shared between the radio terminals comprising traffic channels and control channels associated with traffic channels, some of the transmitted blocks being positively or negatively acknowledged by the radio terminals. With regard to a radio terminal: a quality indication relative to said traffic channel is determined; a quantity relative to acknowledgements transmitted to the base station beforehand is determined; a transmission power on the traffic channel and / or the associated control channel is calculated, for the next corresponding transmission time interval, from said quality indication and said quantity relative to acknowledgements.

The present invention provides a method for associating multiple users with a shared downlink channel. One embodiment of the method may include associating an identifier with a plurality of mobile units and providing at least one multicast service to the plurality of mobile units over a shared channel using the identifier. Another embodiment of the method may include receiving at least one multicast service over a shared channel using an identifier associated with a plurality of mobile units.

A system, method and article of manufacture are provided for managing the transmission suitability of a channel in a multi access scheme. In general, information relating to noise associated with a channel is obtained. A potential effect of the noise on a transmission quality of the channel is then estimated based on the obtained information. Next, a rating is assigned to the channel based on the estimated potential effect. Based on the assigned rating, the channel is classified into a grade of service class. Information relating to the channel and its associated rating and grade of service class is then stored in a database.

The invention includes a method and apparatus for aligning a plurality of data channels using a deskew bitstream. The method includes receiving the deskew bitstream, identifying an aligned deskew frame by processing the deskew bitstream, identifying a data channel alignment position associated with each of the plurality of data channels by comparing a deskew channel comparison bit from the aligned deskew frame to a data channel comparison bit from each of the plurality of data channels, and selecting the plurality of data channel alignment positions associated with the respective plurality of data channels for aligning the plurality of data channels. The plurality of data channels are aligned in a manner for substantially reducing skew associated with the data channels. The deskew bitstream comprises a plurality of data bits associated with the data channels and a plurality of parity bits generated using at least a portion of the data bits.

A wireless communications device which may include a wireless receiver for receiving wireless signals comprising unknown data portions over a channel, and a demodulator connected to the wireless receiver. The demodulator may be for estimating a delay spread and a fade rate associated with the channel, determining a desired time-domain interpolation filter based upon the estimated fade rate, and determining a desired frequency-domain interpolation filter based upon the estimated delay spread. The demodulator may further generate channel estimates for the unknown data portions based upon the desired time-domain interpolation filter and the desired frequency-domain interpolation filter, and determine the unknown data portions based upon the channel estimates.

A base station for use in a wireless network communicating with a plurality of subscriber stations. The base station transmits in a downlink channel to a first subscriber station using a plurality of transmit antennas. The base station transmits to the first subscriber station using either a transmit diversity scheme or a beamforming scheme according to the amount of correlation between the transmit antennas observed at the first subscriber station. The base station also transmits to the first subscriber station using a cyclic delay diversity scheme having either zero delay or non-zero delay according to the amount of antenna / channel correlation observed at the first subscriber station.

A method and apparatus are provided for automatic data rate control in wireless communication systems, such as wireless LANs. A wireless communication device according to the present invention includes a data rate controller that adapts a transmission rate based on a channel correlation measure. The channel correlation measure may be, for example, eigenvalues or singular values of a channel matrix. The data rate controller may also consider the signal quality, channel delay spread or both in determining a data rate.

A system and method of reducing a channel switching delay in TDM mobile television systems comprises transmitting a sequence of data bursts associated with channels for reception on a RF channel bandwidth received on a mobile television receiver; switching between an active state of transmission and a non-active state of transmission during reception of channels on the RF channel bandwidth, wherein the active state of transmission comprises transmission of data bursts associated with user-preferred channels and the non-active state of transmission comprises transmission of data bursts associated with user non-preferred channels; anticipating a particular user-preferred channel that a user will likely switch to during reception of channels on the RF channel bandwidth; decoding the sequence of data bursts during the active state of transmission; buffering one decoded data burst for each of the user-preferred channels; and replacing a previously buffered data burst with a newly buffered data burst.