792 results about "Channel correlation" patented technology

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.

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).

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.

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.

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 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.

Methods, apparatuses, and systems are presented for switching between channels of encoded media data involving receiving encoded media data including reference frames and dependent frames for a plurality of channels, wherein each dependent frame refers to at least one reference frame. Frames associated with a first channel from the plurality of channels are decoded to generate a decoded signal for the first channel. While decoding frames associated with the first channel, data corresponding to at least one reference frame associated with a second channel from the plurality of channels are stored. In response to a control signal for switching from the first to the second channel, at least one dependent frame associated with the second channel is decoded by utilizing the stored data corresponding to the at least one reference frame associated with the second channel, to generate a decoded signal for the second channel.