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 communication system includes a transmitter that transmits both wideband data and narrowband data on a link and a receiver that receives the wideband data and the narrowband data on the link. The receiver demultiplexes the wideband data and the narrowband data into separate data streams so that the link effects transmission of a narrowband channel and a wideband channel. The system achieves high link availability on a link using bandwidth efficient modulation by using a more robust modulation format for the narrowband channel to enable higher link availability for the narrowband channel (carrying the narrowband data on the link) than for the wideband channel. The link may employ bandwidth efficient modulation or may be compatible with prior art wideband modulation formats.

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.

The method for compressive sensing (CS) and reconstruction of ultra-wideband (UWB) channels includes building four practically-based dictionaries related to the antenna angles of transmission and angles of arrival that enhance the sparsity of UWB signals. The dictionaries account for the practical effects of the channel, such as pulse dispersion and the unavoidable effects of the antenna. Utilizing the practically-based dictionaries CS is able to reconstruct the UWB signals more efficiently with reasonable complexity. In addition to waveform reconstruction, the dictionaries are used for channel estimation. The CS method can be used with either a single-shot full profile correlator or a Rake receiver. The Rake receiver employs CS in adjusting its parameters to take advantage of the energy available in the strongest propagation paths.

This invention prevents a periodically reported Rank Indicator from interfering with a similarly periodically reported wideband and subband channel quality indicator. Such interference is disadvantageous because it may eliminate wideband channel quality indicator reporting or eliminate each first bandwidth part of subband channel quality indicator reporting. Proper selection of the rank indicator reporting periodicity and offset relative to the wideband and subband channel quality indicator reporting periodicity prevents this interference.

A method (20) of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels (30) within a noncontiguous wideband channel (24) is provided. The method (20) determines an SNR for each of the subchannels (30). The method (20) then designates a subchannel (30) as clear (93) when its SNR is greater than a least-SNR threshold (70), as impeded (95) when its SNR is less than the least-SNR threshold and greater than an SNR-evaluation threshold, and as obstructed (111) when its SNR is less than both the least-SNR and the SNR-evaluation thresholds. The method (20) then transmits OFDM data (34) so that each of the clear subchannels receives the OFDM data (34) at a maximum subchannel signal level (40), each of the impeded subchannels receives the OFDM data (34) at an intermediate subchannel signal level (42), and each of the obstructed subchannels receives the OFDM data (34) at zero subchannel signal level (44).

A system and method for the efficient use of satellite radio modems and satellite bandwidth is disclosed. In the system and method, a satellite radio modem is used for PRACH requests, each PRACH request occupying 31.25 kHz in a packet data transfer channel. The packet data transfer channels can be either 125.0 kHz or 156.25 kHz. Therefore, four PRACH requests can be transmitted in any one packet data transfer channel. The packet data transfer channels are broken into eight time slots, and one time slot in each channel (either the odd frame or even frame) is dedicated to a PRACH request. A satellite radio modem for PDCH transfers is dedicated for each channel. The satellite radio modem assigned to receive the four PRACH requests is timeshared over 16 channels, thereby reducing the amount of satellite radio modems that would otherwise have been needed, had the PRACH request transmissions utilized a dedicated modem for each PRACH request, for each channel.

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.

A method, system, and base station for providing subband signal to noise ratio (SNR) correction in the scheduling of communication resources. A Scheduling Correction (SC) utility receives periodic subband and wideband channel quality indicator (CQI) reports from one or more wireless devices. The SC utility records a subframe report period for a respective subband CQI report. The SC utility calculates the age of the subband report to determine whether the subband CQI report remains valid. If the subband report is invalid, the SC utility utilizes the wideband CQI report for (current) transmission scheduling. However, if the subband report is valid, the SC utility utilizes: (a) the subband CQI report for transmission scheduling from the most current reporting subframe; or (b) a modified subband CQI value with a correction that utilizes the wideband CQI report, if the subband CQI report was not received at the most current reporting subframe.

A method and system for enhancing the performance of wideband digital RF transport systems, which enables the selection of a serial data rate to be transported over a transport medium. Thus, the present invention allows the system to be adapted to different transport mediums, and allows the user to set the serial data rate based on the input bandwidth of the system. The present invention also 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 present invention allocates the bandwidth segments proportionally so that an optimum amount of bandwidth can be transported at the serial bit rate.

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 invention discloses a wideband wireless channel simulator and a relative method, wherein the device comprises at least one signal channel, a computer controller, a computer, and a channel data exchanger. The signal channel receives and sends radio signal, the computer controller receives and buffers the channel parameter and control command generated by the computer, and transfers data to each signal channel, the computer bears an operation module simulated by the wideband wireless channel, while the operation module generates channel data and communicates with the computer controller, and the channel data exchanger exchanges data between signal channels. The invention can realize quick and accurate simulation of wideband channel, particularly for simulating the condition which uses antennas to send and / or receive signal transmitted in wireless channel. The inventive device has simple structure and easy application.

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.

Methods, systems, and devices are described for wireless communication at an AP. A station (STA) serving as a soft access point (SAP) in master mode may be configured to support communication over two radar channels (e.g., a primary and secondary channel) simultaneously. The STA may detect radar on the primary channel and move the primary channel to the secondary channel; meanwhile, the secondary channel may be moved to a channel in a non-radar subband. In some cases, the STA may establish a primary channel in a non-radar subband and then advertise a single bandwidth capacity. the STA may then perform a channel availability check (CAC) on a radar subband. If the CAC is successful, the STA may establish a secondary channel on the radar subband (or move the primary channel to the radar subband) and advertise a dual bandwidth capacity.

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 provides a solution of designing a two-stage codebook set applicable to 4Tx cross-polarized antenna configuration and a method of determining a codebook in a multi-input multi-output communication system based upon the designed two-stage codebook set applicable to 4Tx cross-polarized antenna configuration. The first stage codebook relates long-term / wideband channel information and is based on DFT vectors, whereas the second stage codebook relates to short-term / narrowband channel information and is base on selecting columns of the first stage codebook and providing inter-polarization phase information.

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 methods of processing signals subjected to interference. It consists, when this signal is formed of a first wideband channel and of a second narrowband channel modulating one and the same carrier in which these signals are cut off for the duration of the interference, in using a single phase loop and a single code loop to process these two channels simultaneously. It makes it easier to process signals in satellite based navigation systems of the GPS type when they are scrambled by the DME-type distance measuring system signals, as well as more generally making it possible to increase the robustness of the processing by joint processing of the bands broadcast to the users.

A feedback method of channel state information comprises the following steps: in the mode supporting closed-loop space multiplexing, user equipment (UE) uses at least two report types to feed back the channel state information, wherein when the rank RI of the channel is not more than M, the UE uses a code word W1 and a code word W2 to jointly represent the subband or wideband channel information, the report type A includes the indication information of the rank RI of the channel and the indication information of partial code word W1 and the report type B includes the indication information of the code word W2 and the indication information of partial code word W1; and when the rank RI of the channel is more than M, the UE uses one code word W to represent the subband or wideband channel information and feeds the indication information of the code word W back to a base station or does not feed back the code word information, or the UE uses a fixed matrix and code word W to jointly represent the subband or wideband channel information. The method satisfies the requirement of the LTE-A system and dispenses with PUCCH expansion.

A wave-form generator drives a number of microwave generating devices each operating at different frequency bands. The output of each microwave generator is connected to its own transmission channel of limited bandwidth which contains all the non-linear components necessary for transmission such as an amplifier, T / R switch, rotary joint and beam switch. These individual channels are finally combined onto a common wideband channel which contains only substantially linear components such as a single waveguide and the antenna itself. Because of the isolation between channels there is little or no opportunity for the generation of harmonics or intermodulation distortions which would otherwise occur in a transmitter capable of operating over a very wide bandwidth.

An oscillation frequency changing means is inserted between a tuner and an oscillator of local oscillator (56) of a high frequency receiving device, and the oscillation frequency changing means, in each frequency band received, changes the oscillation frequency characteristic of local oscillator (56) in relation to the tuning voltage supplied from PLL circuit (78), and operates in accordance with the frequency characteristic of tuning filter (52, 54, 62, 64) to obtain an oscillation signal varied just by a predetermined frequency, thereby making it possible to receive broadband channels of continuous VHF broadcast band and UHF broadcast band.

The invention discloses a method and a device for quantizing channel state information. According to the embodiment of the method and the device for quantizing the channel state information, the method that codeword indexes are provided for a base station from a user terminal is provided, the base station is provided with antennas, the number of the antennas is Nt, and the antennas are evenly arranged in a circular array. The method for quantizing the channel state information includes the following steps: according to an estimated wideband channel matrix, the user terminal determines a first codeword in a first codebook on the basis of a first predetermined rule, wherein the sequence of the first codebook is r, the first codeword is a group of beams for estimation of the wideband channel direction, and the r is equal to a positive integer from 1 to Nt; the codeword index of the first codeword is sent to the base station; for each subband, according to an estimated subband channel matrix, the user terminal determines a second codeword in a second codebook on the basis of a second predetermined rule, wherein the sequence of the second codebook is the r, the second codeword is used for describing the subband channel direction and is one wave beam in the first codeword; and then the codeword index of the second codeword is sent to the base station. Through the method and the device for quantizing the channel state information, a quite high system performance gain can be obtained at quite low PMI feedback cost.

The invention relates to improved utilization of modems for data communication and particularly, although not necessarily exclusively, relates to use of wideband modems. The invention relates to a method for allocating groups of channels to users or groups of users in an improved manner, such that at least one of the channels in a group of channels is available to both a first user or group of users and a second user or groups of users. This is in contrast to the conventional method where typically a group of channels is only available to one user or group of users. The present invention provides large advantages over the conventional method for communications and increases the capacity for burst rate data communication via the modem.

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.

The invention provides a terminal and system capable of adaptively switching wideband and narrowband communication, and a communication method thereof. The terminal comprises an adaptive switching module, a control module, a power supply module, a narrowband communication module and a wideband communication module; the control module separately drives and controls the adaptive switching module, the narrowband communication module and the wideband communication module; the system comprises multiple terminals for adaptively switching wideband and narrowband communication, a narrowband frequencypoint distribution module, multiple narrowband channels and one or more wideband channels; the adaptive switching module is controlled through the method in the invention; switching of narrowband communication or wideband communication is adaptively carried out according to the size of data to be sent; the bandwidth utilization rate is increased; the narrowband delay phenomenon due to relatively big data or the bandwidth waste phenomenon due to relatively small data can be improved; multiple frequency points are set; when one terminal is communicated with multiple other terminals at the same time, influence on communication with another terminal due to occupation of one channel can be avoided; therefore, the communication efficiency is increased; and the channel utilization rate is increased.