84 results about "Wideband channels" patented technology

The present invention has particular applications to the navigation of Internet web pages using two-way interactive communication devices, such as a mobile device, a mobile phone, a landline telephone, and an Internet capable remote controller. According to one aspect of the present invention, each of the two-way interactive communication devices is a node in a distributed network, thus the devices can access hypermedia or hierarchic layers of information stored in server devices on the network. When one or more pages of information are updated, rather than sending the entire updated information to users of the devices subscribing to the updated information through the network, the present invention sends a notification to a proxy server that forwards the notification to the users using a messaging system via a low cost narrowband channel. Upon receiving the notification, the users can fetch the updates, when needed, through a wideband channel. Hence systemic solutions are provided in the present invention to integrate wideband and narrowband channels so as to keep the users informed of any updates to their desired information and meanwhile provide efficient means to the users for retrieving the latest updates without incurring uncontrollable costs and increasing unnecessary network traffics.

The present invention has particular applications to the navigation of Internet web pages using two-way interactive communication devices, such as a mobile device, a mobile phone, a landline telephone, and an Internet capable remote controller. According to one aspect of the present invention, each of the two-way interactive communication devices is a node in a distributed network, thus the devices can access hypermedia or hierarchic layers of information stored in server devices on the network. When one or more pages of information are updated, rather than sending the entire updated information to users of the devices subscribing to the updated information through the network, the present invention sends a notification to a proxy server that forwards the notification to the users using a messaging system via a low cost narrowband channel. Upon receiving the notification, the users can fetch the updates, when needed, through a wideband channel. Hence systemic solutions are provided in the present invention to integrate wideband and narrowband channels so as to keep the users informed of any updates to their desired information and meanwhile provide efficient means to the users for retrieving the latest updates without incurring uncontrollable costs and increasing unnecessary network traffics.

A system and method for enhancing the performance of wideband digital RF transport systems is disclosed, which enables the transport of different bandwidth segments on a plurality of wideband channels by selecting an optimal clock sample rate for each bandwidth segment to be transported. Thus, the bandwidth segments are proportionally allocated so that an optimum amount of bandwidth can be transported at the serial bit rate.

A method and apparatus for performing effective feedback in a wireless communication system supporting multiple antennas. A method for transmitting CSI of downlink transmission via uplink in a wireless communication system includes transmitting a joint-coded rank indicator (RI) and a first wideband (WB) precoding matrix indicator (PMI) at a first subframe, and transmitting a wideband channel quality indicator (WB CQI) and a second WB PMI at a second subframe. A user equipment (UE) preferred precoding matrix is indicated by a combination of the first PMI and the second PMI. If the RI is Rank-1 or Rank-2, the first PMI indicates one of subsets each having 8 indexes from among 16 indexes of the first PMI of a precoding codebook.

A system and method for enhancing the performance of wideband digital RF transport systems is disclosed, which enables the transport of different bandwidth segments on a plurality of wideband channels by selecting an optimal clock sample rate for each bandwidth segment to be transported. Thus, the bandwidth segments are proportionally allocated so that an optimum amount of bandwidth can be transported at the serial bit rate. As one example, a system for enhancing the performance of a wideband digital RF transport system is disclosed, which includes a transmit unit, a receive unit, and an optical transmission medium connected between the transmit unit and the receive unit. The transmit unit includes a plurality of wideband RF analog signal inputs coupled to a plurality of analog-to-digital, digital down-converter (A / D DDC) devices. Notably, the sample rate of each A / D DDC device is determined by a respective sample clock. The digitized wideband RF segments at the outputs of the A / D DDC devices are combined and converted to a frame structure, converted to serial form, and transmitted on the optical transmission medium to the receive unit. A light detector device in the receive unit detects the serial bit stream on the optical transmission medium, the serialized frames are converted back to the original frame format, and the original digitized wideband RF segments are reconstructed. Each digitized wideband RF segment is coupled to a respective D / A digital up-converter (D / A DUC) device associated with a particular wideband RF signal input on the transmit side. Notably, the output sample rate of each D / A DUC device is determined by a respective sample clock, which provides the same sample rate as that of the associated A / D DDC device in the transmit unit. The sample rate of each A / D DDC device (and associated D / A DUC device) is pre-selected so that the transmission medium can transport the optimum amount of RF bandwidth at the given serial bit rate.

A method and apparatus for performing effective feedback in a wireless communication system supporting multiple antennas. A method for transmitting CSI of downlink transmission via uplink in a wireless communication system includes transmitting a joint-coded rank indicator (RI) and a first wideband (WB) precoding matrix indicator (PMI) at a first subframe, and transmitting a wideband channel quality indicator (WB CQI) and a second WB PMI at a second subframe. A user equipment (UE) preferred precoding matrix is indicated by a combination of the first PMI and the second PMI. If the RI is Rank-1 or Rank-2, the first PMI indicates one of subsets each having 8 indexes from among 16 indexes of the first PMI of a precoding codebook.

Methods, systems, and devices for wireless communication are described. One method includes identifying a plurality of intermediate precoders corresponding to a plurality of tone subsets. The plurality of intermediate precoders define a plurality of vectors across the plurality of tone subsets. The method further includes selecting, for each vector of the plurality of vectors, a subset of non-frequency domain components of the vector, such as time-domain components; modifying the plurality of intermediate precoders to a plurality of smoothed precoders based at least in part on the selected subset of non-frequency domain components for each vector; and precoding a plurality of transmit streams using the plurality of smoothed precoders. The plurality of smoothed precoders is smoothed in a frequency domain compared to the plurality of intermediate precoders. Smoothing precoders may enable application of wideband channel estimation techniques using user equipment (UE)-specific reference signals.

A meter data collection system in which a licensed narrowband frequency channel is used to wake up carrier-sensed, battery-powered meter reading devices (MRDs) is disclosed herein. In the meter data collection system disclosed herein, an unlicensed wideband channel is used to transmit data replies from the MRDs to a mobile data collection device. In another embodiment disclosed herein, a meshed network of MRDs communicating on the unlicensed channel is combined with a roaming interrogator that uses the licensed channel to send commands or to perform on-demand reads.

The embodiment of the invention discloses a channel information feedback method, a terminal and a base station. The method comprises the steps as follows: channel information without optimal subband position is reported to a base station; the channel information without the optimal subband position I comprises a wideband channel quality indication CQI and the CQI of the optimal subbands in each bandwidth; and the channel information with the optimal subband position is reported to the base station when a reconfiguration condition is realized. The channel information with the optimal subband position comprises the wideband CQI, the CQI of the optimal subbands in each bandwidth, and the optimal subband position. The invention is suitable for a terminal to implement channel information feedback to the base station.

A narrowband communication system (100) includes a base station (102) and a plurality of subscriber units (104). The base station assigns one or more wideband channels to be measured to each subscriber unit (606). The subscriber units tune to their assigned wideband channels and perform narrowband measurements, then report the results to the base station (612). The base station then analyzes the measurement results (614) and selects available wideband channels to be divided into narrowband channels for use by the narrowband system.

The invention discloses a method for extracting parameters of wideband channels and a device thereof, and a method for realizing wideband channel emulation of channel modeling and a device thereof based on the channel parameters obtained by the method for extracting parameters of wideband channels. The method for extracting parameters of wideband channels comprises the following steps: a noise bottom is calculated according to the measured channel impulse response; a signal component threshold is determined according to the noise bottom; local maximum points and local minimum points are searched in the effective signal components divided by the signal component threshold, and the channel impulse response between two adjacent local minimum points of the local maximum point is taken as a component channel; and channel parameters are extracted on each channel in parallel. Due to the invention of the method, the slow velocity of convergence of the parameter extraction of wideband channels and the extraction accuracy can be improved; using the extracted channel parameters for channel emulation can respond the characteristics of the practical communication environment accurately; and the implementing complexity of the method is low.

The invention relates to a partitioned mixed channel modeling method based on a cluster delay line in a high-speed railway viaduct scene. The method comprises the steps of multipath component extraction and clustering of measured channel impulse responses; data partitioning according to changes of the number of clusters; calculation of the relative delay time of cyclically moving reflective paths in a cluster form relative to direct reflective paths in a cluster form, and separation of theoretical model data and statistical model data; analysis of the statistical model data; analysis of the theoretical model data; establishment of a partitioned mixed channel model based on the cluster delay line in the high-speed railway viaduct scene. By adopting the method, the overall characteristics of wideband channel changes can be reflected via inter-cluster characteristics, and details of wideband channel changes can be reflected via inner-cluster characteristics, regular effects on channel multipath characteristics resulting from regular buildings on two sides of tracks can be reflected, and irregular effects on channel multipath characteristics resulting from rapid scenery changes around trains can also be reflected.