523 results about "Channel capacity" patented technology

A radio communication apparatus is disclosed that enables the influence of the feedback information on the channel capacity to be kept to the minimum without reducing the transmission efficiency of information by transmission of pilot symbol. In the apparatus, a delay dispersion measuring section (272) generates a delay profile using the received signal, and measures delay dispersion indicative of dispersion of delayed versions. A moving speed estimating section (274) estimates moving speed of a mobile station apparatus that transmits a pilot symbol based on the variation in reception power of the pilot symbol. An other-cell interference measuring section (276) measures other-cell interference caused by signals transmitted in cells except the cell to which the apparatus belongs. Corresponding to the delay dispersion, moving speed and other-cell interference, a pilot pattern information generating section (278) selects a pilot pattern such that placement of pilot symbol is optimal in a frame, and generates the pilot pattern information.

A class of bandwidth reduction techniques are used develop a broad class of modulation types collectively called SSB-FM. These signals can be used to construct communication systems that provide bandwidth-normalized performance gains of 10 dB or more when compared to popular prior art modulation methods. An aspect of the invention involves mapping trellis paths in a complex signal space onto corresponding real-valued trellis signals with desirable spectral properties. The invention can be used map continuous phase modulated (CPM) signals onto simpler amplitude-modulated trellis signals having double the channel capacity of prior art CPM signals. Multi-amplitude signaling and frequency division multiplexing may also be incorporated to further accommodate more information per symbol.

The present invention allows a wireless communication system, such as a base station, to select N antennas from an associated group of M antennas for transmitting multiple streams of data to a given user. Based on the channel conditions between the M antennas of the wireless communication system and the multiple antennas at the receiver, the N antennas to use for transmission are selected to enhance channel capacity, signal-to-noise ratios, or a combination thereof. The channel conditions are measured at the receiver, and may be sent back to the wireless communication system for processing or may be processed at the receiver, wherein instructions are transmitted back to the wireless communication system to control antenna selection.

A communications system for an aircraft carrying personnel having personal electronic devices (PEDs) for wireless data communications outside the aircraft includes a ground-based communications network, and an access point in the aircraft for providing a WLAN for data communications with the PEDs. An air-to-ground transceiver in the aircraft cooperates with the access point for data communications with the ground-based communications network. At least one data traffic controller selectively allocates data communications channel capacity between the PEDs and the ground-based communications network.

Idle Video-On-Demand (VOD) channel capacity is used to deliver promotional content to selected set-top boxes (STBs) in a cable television network. Commercial segment cues are used to instruct a set-top box to switch away from a broadcast program to the VOD channel during a commercial segment, and then switch back again to the original broadcast program at the end of the segment.

More particularly, a promotion server determines an asset to be distributed such as a targeted promotion item (e.g., a commercial), and a list of STBs that are to receive it. The promotion server causes the video promotion content to be stored in VOD servers located at the head ends. A scheduler process then delivers schedule messages to head end message servers which identify each promotion asset, and an STB which is to receive it. The head end message server notifies its associated VOD server which then cues the asset by loading the asset, starting the asset, but pausing it. Prior to the occurrence of a commercial slot in a broadcast program, an asset trigger is inserted into the broadcast stream at the head end. This asset trigger contains general information concerning the asset to be sent, and an idle VOD channel number. The STB receives the asset trigger and readies itself to tune to the VOD channel when cued for at the beginning of a commercial segment, but does not yet tune to the VOD channel. Upon detection of a commercial cue tone in the broadcast channel, the head end message server sends a tune away trigger to the STB, and also instructs the VOD server to start playing the cued promotion. When the STB receives a tune away trigger, it switches from the broadcast channel being played to the selected idle VOD channel, and the promotion is viewed.

The invention relates to a frequency and power distributing method based on an NOMA (non-orthogonal multiple access) system. The frequency and power distributing method comprises the following steps: confirming a user set for sending information to a cell by a base station and obtaining CSI (channel state information) of the user set at a base station end; distributing each sub channel to a user with the best CSI condition, and regarding the user as a strong user; based on this, combining the strong user with other users in sequence, calculating a maximum channel capacity value of each pair of sets, selecting one pair of set with maximum channel capacity value, and regarding another user in the set as a weak user; distributing two users which are respectively the strong user and the weaker user on each sub channel, wherein the set comprising the strong user is a strong user set Omega A, and the set comprising the weak user is a weak user set Omega B; performing optimal power distribution on the strong user and the weak user on each sub channel respectively. The method can meet large-scale user transmission needs in the future, and increases access probability of the user, so that the spectrum efficiency of the system is improved.

A mobile communication system comprises a detecting unit to detect information concerning a moving speed of a mobile terminal, and a selection controlling unit to select a use frequency in a higher frequency band when the speed information detected by the detecting unit is a higher speed, while selecting the use frequency in a lower frequency band when the detected information is a lower speed, and assigning it to the mobile terminal. In a mobile communication system in which a relationship between a terminal moving speed (Doppler frequency) and transmission quality degradation is non-monotonous, the communication quality can be improved and the channel capacity can be increased.

Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. A first of the acoustic sensors detects a communication signal that propagates along a tubing string in a first direction. A second of the acoustic sensors is configured to detect the communication signal before the first acoustic sensor. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. Such signal suppression may significantly enhance the communication signal's signal-to-noise ratio, thereby increasing channel capacity. The acoustic telemetry device may be configured to support logging while drilling and/or full-duplex communication.

The present invention discloses a method for increasing the channel capacity of a communications network, comprising a plurality of one-way TDMA transmitters sharing said channel, and at least one compatible receiver, by reducing transmission collisions among said transmitters. This is achieved by coupling a Global Navigation Satellite System (GNSS) decoder, such as a GPS receiver, to each transmitter, and limiting transmissions to discrete time slots, determined by timing signals provided by said GNSS. Further, this basic set of time slots is divided into several sub sets, and each transmitter selects a sub set of time slots according to its geographic location, in order to enable reusing time slots in spaced apart areas, as frequencies are reused in cellular networks. Then, each transmitter selects its own transmission time slot, from said sub set, in a way that statistically minimizes collisions among nearby transmitters. The present invention does not intend to ensure collision-free communications, yet is projected to reduce the transmission collision rate among simplex in nature transmitters, which have no means to detect other transmissions, or discover if a transmission was successful. One embodiment of this invention is related to distress radio beacons in satellite based Search and Rescue (SAR) systems, such as Cospas-Sarsat.

A self-adapting method which is used for a relay strategy of a multiple-relay cooperative communication respectively selects an appropriate retransmission mode and distributes a corresponding transmission power for each relay code according to the state of current real-time channel. Or a direct transmission mode is decided to be selected in order to realize the maximization of the channel capacity of the system and provide a high-efficiency communication under the state of reliability. The method mainly comprises the following operation procedures: (1) estimating the channel, (2) selecting a cooperative partner, (3) choosing an optimum relay strategy for each rely with the result of channel estimation and partner selection, (4) respectively calculating the capacity of the direct transmission channel and the capacity of the channel of the selected relay plan according to the formula of channel capacity, and (5) taking the plan with larger capacity of the equivalent channel as a final selection result. The method determines whether the relay is used according to the current channel state, and selects an optimum retransmission strategy for each relay under the precondition that the reliability and availability of the communication are considered and reasonably distribute power between the signal source and each relay.

Rate matching and rate shaping methods and systems for managing data traffic on wireless channels are disclosed. Rate matching embodiments dynamically determine downlink video data transmission rates based on frame decoding deadlines and frame sizes. In addition, if the channel capacity cannot support the video data transmission rate, the rate matcher can adjust the video stream accordingly so that it is supportable by the channel capacity. In turn, rate shaping implementations can tailor the transmission rate shaping based on the state of the wireless data channel. Shaper operations can be specifically adapted to a saturated state of the wireless channel, to an unsaturated state of the wireless channel and to transitions between the unsaturated and saturated states.

A channel capacity is increased by using MIMO (multiple input multiple output) radio relaying system.

A transmission is made from a transmitter 10 using a first antenna 11₁ and a second antenna 11₂ having polarization characteristics which are orthogonalized to each other. A reception is made in a repeater 20₁ using reception antennas 21₁ and 21₂ each having the same polarization characteristic as the first and the second antenna 11₁ and 11₂, respectively. Each signal received by the first and the second reception antenna 21₁ and 21₂, respectively, is passed through loop interference suppressors 27₁ and 27₂, respectively, and through amplifiers 24₁ and 24₂, respectively, to be transmitted from the first and the second transmission antenna 21₁ and 21₂ having the same polarization characteristics as the second and the first antenna 11₂ and 11₁, respectively. A reception is made in a receiver 30 by antennas 31₂ and 31₄ having the same polarization characteristic as the first antenna 11₁, and the reception is also made by antennas 31₁ and 31₃ having the same polarization characteristic as the second antenna 11₂. These received signals are subject to a signal separation processing in MIMO equalizer 32.

The present invention advantageously provides a method and apparatus for optimization of channel capacity in multi-line multi-tone communications such as X-DSL among subscriber lines which are bundled with one another. In an embodiment of the invention an apparatus for optimizing channel capacity of multi-tone communications effected by opposing sets of modems coupled to one another by a plurality of subscriber lines is disclosed. The apparatus includes a spectrum manager coupled to at least one of the opposing sets of modems. The spectrum manager includes: a profiler, a demand module and an optimizer. The profiler obtains from the at least one of the opposing sets of modems the spectral characteristics of each of the plurality of subscriber lines. The demand module determines for each of the plurality of subscriber lines the subscriber demand profile. The optimizer defines target parameters for at least one of bit loading, and power spectral density (PSD) for selected tones of the multi-tone communications based on the spectral characteristics from the profile module and the demand profiles from the demand module and downloads the target parameters to the at least one of the opposing sets of modems.

Systems and methods in which data compression techniques are utilized to fill a predetermined channel capacity are shown. According to one configuration, event data points within test data are selected for communication via the data communication channel and a data decimator is utilized to identify other data points within the test data to fill or substantially fill the predetermined channel capacity. The foregoing data decimator may employ one or more variables for selecting data for communication, wherein one or more of the variables are preferably adjusted in decimator iterations to select an optimum or otherwise desirable subset of data for communication. Data decimators may additionally or alternatively implement a suitable “growth” function to select the particular data for communication and/or the amount of data communicated.

The invention relates to a multidimensional constellation mapping based coding and modulating method, demodulating and decoding method and system. The coding and modulating method comprises the following steps of: carrying out channel coding and bit interleaving on input information bits to obtain coded interleaved bits; carrying out K-dimensional pulse amplitude modulated constellation mapping on the coded and interleaved bits to obtain a constellation mapping symbol of a K-dimensional real-number vector, wherein K is a positive integer; carrying out constellation rotation on the constellation mapping symbol to obtain a multidimensional rotated constellation mapping symbol of the K-dimensional real-number vector; and carrying out dimension conversion and general real-number interleaving on the multidimensional rotated constellation mapping symbol to obtain a coded and modulated symbol, and outputting the coded and modulated symbol. The method and system in the invention can ensure that the performances of a coding and modulating system and a corresponding demodulating and decoding system approach the channel capacity at medium and low frequency spectrum efficiency under the AWGN (Added White Gaussian Noise) and fading channel conditions and meanwhile, the throughput of the system is taken into consideration.

Methods, systems and devices are described for a direct-sequence spread-spectrum communication scheme that increases the number of users by utilizing a plurality of closely spaced orthogonal carriers that produce overlapping spectra. A method includes overlapping a plurality of direct-sequence spread-spectrum signals using carrier frequencies that are orthogonally spaced relative to a bit rate. The methods, systems and devices provide advantages because they can accommodate an increase in the number of normalized users and can optimize the loading of users across multiple frequency channels.

A multi-user scheduling method for the down link in multi-input multi-output antenna system includes such steps as choosing a subset of emitting antenna on base stating by user terminal, feeding back the indicator of the antenna subset and channel state information, and determining the distribution relation between emitting antenna and user terminal in next transmission time slot according to scheduling algorithm.

Techniques to process a number of “received” symbol streams in a Multiple-Input Multiple-Output (MIMO) system with multipath channels such that improved performance may be achieved when using successive interference cancellation (SIC) processing. In an aspect, metrics indicative of the quality or “goodness” of a “detected” symbol stream are provided. These metrics consider the frequency selective response of the multipath channels used to transmit the symbol stream. For example, the metrics may relate to (1) an overall channel capacity for all transmission channels used for the symbol stream, or (2) an equivalent signal-to-interference noise ratio (SNR) of an Additive White Gaussian Noise (AWGN) channel modeling these transmission channels. In another aspect, techniques are provided to process the received symbol streams, using SIC processing, to recover a number of transmitted symbol streams. The particular order in which the symbol streams are recovered is determined based on the metrics determined for symbol streams detected at each SIC processing stage.

In all-optical networks, optical switching and routing become the most important issues for interconnecting the transport network layers. This invention describes a novel tunable optical add/drop filter for the all-optical wavelength-division-multiplexing (WDM) network applications. This filter can add or drop part of the high transmission capacity signals of a WDM link. It can be used to decentralized access point in the access network or as small core network node to realizing branching points in the network topology. It works in both wavelength and space domains. It has the advantages of: 1) High throughput and low voltage operation; 2) Wide tuning range and therefore, high channel capacity; 3) High isolation and high directivity between input and output ports; 4) Compact device packaging is possible as compares to the conventional grating and mechanical switching type of add/drop filter; 5) Multiple ports add/drop tunable filters can be realized with this invention to interconnect multiple WDM networks. This novel add/drop filter can be used in various WDM topologies. It enhances the performance of the conventional tunable filter by re-routing the rejected wavelengths back to network, which not only save the precious optical energy, but also cut down the return loss of the device.

The invention relates to a code modulation method, demodulation and decoding method and system which are used for digital communication systems. The code modulation method comprises the following steps of: carrying out channel coding and bit interleaving on an input information bit to obtain a code bit; and carrying out M-point K-dimensional Gaussian constellation mapping on the code bit to obtain a constellation mapping symbol, i.e. a K-dimensional real number vector, wherein M and K are both integers more than 1. The method and the system can ensure that the performances of a code modulation system and a corresponding demodulation and decoding system approach channel capacity in high and low frequency spectrums under the condition of a plurality of channels, such as AWGN (Additive WhiteGaussian Noise), attenuation and the like, and consider the throughput capacity of the system at the same time.

The invention discloses a network access method of machine-to-machine (M2M) terminals. The network access method comprises the steps of: S1, dividing a plurality of M2M terminals into a plurality of M2M groups by a base station into so as to ensure that the M2M terminals belonging to the same M2M group have a same business type and a same service quality level; S2, electrifying the M2M terminals to realize initial uplink synchronization and keeping an uplink synchronization state; S3, calculating the channel capacity of a PRACH (Physical Random Access Channel) and the channel capacity of a PUCCH (Physical Uplink Control Channel) of a current system; and S4, when the M2M terminals generate uplink data to be sent, preferentially sending scheduling requests through the PRACH, and when the PRACH undergoes collision, dynamically distributing PUCCH scheduling request resources to the M2M terminals by the base station and sending the scheduling requests by the M2M terminals through the PUCCH. According to the method disclosed by the invention, the congestion of the PRACH is alleviated, and the service quality requirements of the M2M business terminals are finally met.

There is provided a channel capacity estimation method for adaptive video transmission, the method including: estimating a Bit Error Rate (BER) for a received video packet; and estimating channel capacity by using the estimated BER.

An antenna weight estimation method in a mobile communication system is capable of improving the accuracy of antenna weight estimation values, thereby improving communication quality and increasing radio channel capacity. It operates instantaneous estimation and accumulative estimation in parallel, in which the former is made for estimating the antenna weight used for received SNIR estimation for transmission power control, and the latter is made for demodulating the received data. Thus, it can obtain the antenna weight for the received SNIR measurement with a minimum delay, and at the same time, it can improve the reliability of the antenna weight for the data demodulation.

An apparatus and method for controlling amount of information to be fed back in a multiple antenna system in a multi-user environment. The apparatus includes a channel estimator which estimates channel values by using an input signal; a Singular Value Decomposition (SVD) operator which decomposes singular values from the estimated channel values; and a feedback determining unit which uses the singular values to compute channel capacity that can be obtained according to the amount of channel information to be fed back, and selects the channel information to be fed back by using the channel capacity.

A method for transmitting and receiving data in a multiuser Multiple-Input Multiple-Output (MIMO) system including a base station connected to a plurality of user equipments. In the method, each of the user equipments separately calculates channel capacity information using a linear reception scheme and a nonlinear reception scheme, and feeds back the calculated channel capacity information to the base station. The base station separately calculates system capacities using at least two different antenna scheduling schemes based on the channel capacity information fed back from the user equipments, and allocates antennas to the user equipments using a selected antenna scheduling scheme having higher system capacity out of the two antenna scheduling schemes.

A system and method for a transceiver structure, where Different Known Guard Intervals (DKGI) are appended to multiple, consecutive data blocks and are then used in combination with Channel State Information (CSI) to restore cyclic convolution in the time domain. Once restored, the CSI and cyclic convolution are transformed into the frequency domain by FFT processing to facilitate equalization of the channel through Frequency Domain Equalization (FDE). Through performance of time domain channel estimation, there is no need for pilot signals and related overhead, thus channel capacity is enhanced.

The invention discloses a channel capacity optimization method for an intelligent reflector MISO wireless communication system, and the method comprises the steps: building an intelligent reflector MISO wireless communication system model; secondly, representing the channel capacity by using a beamforming emission strategy, and establishing a channel capacity optimization mathematical model, wherein the channel capacity is related to a transmitting beam forming vector v and a reflection matrix phi, and optimally describing the channel capacity as a problem (P1); then, decomposing the problem (P1) into two sub-optimization problems of an optimized transmitting beam forming vector v and an optimized reflection matrix [phi], and obtaining the optimal solutions of v and [phi]; and finally, performing alternate iterative optimization on the two sub-optimization problems until convergence, and taking [phi] as an optimal reflection matrix at the moment, thereby obtaining the final optimization result of the problem (P1). According to the invention, the system performance is optimal by adjusting the reflection coefficient of the reflection matrix; and the adopted alternating optimization algorithm is suitable for configuring a reflection matrix, the calculation complexity is low, and the performance of the intelligent reflecting surface system is effectively improved.

The invention discloses a user pairing method used in uplink multiuser MIMO (MU-MIMO) transmission and a method for determining user pairing factor in a mobile communication system. The user pairing method includes the following steps: a base station measures user receiving signal to noise ratio and the channel matrix formed by users and a base station end; according to channel capacity, the influence on a system caused by fast fading and slow fading is taken into comprehensive consideration; finally, through calculating user pairing factor, the user who has maximum paring factor with the selected user is chosen to complete pairing with the selected user; moreover, data is transmitted. Both methods can realize maximization of system capacity to a certain degree; meanwhile, through introducing an adjusting factor into a pairing factor formula, the throughput and fairness of a system can be flexibly adjusted.

A system for Digital Subscriber Line (DSL) data communications, and therefore the transceiver that contains the transmitter and the receiver implementing such system, based on Single Carrier Modulation (SCM). The invention includes an efficient vectoring structure that provides novel solution for crosstalk (505 and 506) elimination in SCM systems, which allows the cooperative operation at the transmitter (511) side as well as at the receiver (512) side.

The present invention also includes a preamble insertion in a specific location of the transmission path, which makes possible the synchronization, direct channel response (503 and 504) estimation, crosstalk channel responses estimation and noise (507 and 508) estimation in agile manner, to make a continuous tracking of the changes of the channel (503 to 506) and the noise environment (505 to 508). It allows operation with low noise margin.

For approaching the capacity of the channel the present invention also defines the blocks that compose the forward error correction and their corresponding location to operate near to the channel capacity limit.

The present invention relates to a terminal device and to a scheduling method and device for scheduling data transmission over a plurality of channels in a data network. A predetermined parameter, e.g. a TFC value, indicating a channel capacity in a received data stream of at least one of the plurality of channels is monitored, and a request for change of the maximum channel capacity allocated to the at least one of the plurality of channels is determined, if the value the monitored predetermined parameter falls outside a predetermined allowed range. The terminal device is configured to set a predetermined parameter indicating a channel capacity to a value outside the predetermined allowed range in order to request a change of the maximum channel capacity. Thereby, an explicit capacity request signaling from the data source to the scheduling functionality can be avoided without introducing additional latency, and physical layer resources can be increased for improved data transmission.