350 results about "Dynamic channel" patented technology

A method and apparatus for efficiently transmitting channel quality information in an OFDM communication system using dynamic channel allocation and adaptive modulation, and determining parameters required for time-division channel quality information transmission in an asynchronous CDMA communication system are provided. In the OFDM communication system in which a plurality of subcarriers are allocated to a plurality of UEs, the subcarriers are divided into a plurality of subcarrier groups each having at least one subcarrier. Each of the UEs determines and transmits the channel quality information of each of the subcarrier groups according to predetermined transmission parameters at transmission time points that do not overlap with those of other UEs. A Node B dynamically allocates the subcarriers to the UEs and their corresponding modulation schemes according to the channel quality information.

A plurality of base stations communicate with a plurality of mobile units. Each base station includes a base station transceiver that receives inbound information from the mobile units and transmits outbound information to the mobile units. A mobile switching center (MSC) is coupled to the base stations and communicates the inbound information and outbound information with the base stations. The base stations each include signal detectors that detect signal strength of the inbound information, co-channel information and adjacent channel information. The MSC maintains a table of signal strength per communication channel and allocates communication channels to the base stations based on the signal strength information. The inventive dynamic channel allocation includes several channel allocation algorithms that can be active at the same time. Only one of the algorithms is active at a time. The choice of the algorithm is based on current interference conditions and traffic load. The invention is implemented in the MSC and base stations of a digital cellular network using wideband technology for its air interface. While the decision-making mechanism and the channel allocation algorithms are implemented in the MSC, the protocol between the MSC and base stations is extended to support the proposed concept for dynamic channel allocation. Advantages of the invention includes improved communication and reduced interference.

We disclose a method of dynamic channel assignment for wireless transmission systems that employ time or frequency multiplexing, or both time and frequency multiplexing. The invention is specifically addressed to the problem of avoiding interference in the channels of such systems. In a broad aspect, the invention involves partitioning base stations of a network into non-interfering sets. Channels are allocated to the non-interfering sets according to need. Stages of channel reallocation take place periodically. The reallocation takes place through coordinated activity by the base stations. That is, the channel reallocation is carried out in response to information that is exchanged between base stations, or it is centrally directed by the network in response to information passed to the network by the base stations.

Dynamic channel estimation thresholds allow for determining optimal threshold values for channel estimation in a layered-modulation wireless communication system. A channel estimation threshold can be used to remove or otherwise filter out channel estimate components that may be significantly influenced by noise. The channel estimation threshold value can be used to generate a refined channel estimate that is used in decoding multiple layers of a layered modulation signal. The channel estimation threshold value can be varied based on the performance of the various signal layer decoders. The adaptive channel estimation threshold provides for decoding a base layer based on an optimal threshold value for the base layer; determining an error rate associated with decoding the base layer; and using an optimal threshold value for an enhancement layer in a channel estimation algorithm if the error rate is lower than a predetermined level.

A wireless broadband communications system that can maintain high data rates while taking into account channel interference resulting from operating in shared frequency bands, signal fading resulting from dynamic channel degradation, and signal distortion resulting from compliance with maximum power output regulations. In one mode of operation, the system performs adaptive modulation by transmitting a first signal over a selected channel using a first modulation mode having a level of distortion associated therewith resulting from operating the system at a predetermined maximum power output level. Next, a SINAD level is measured on the first channel. The level of distortion associated with the first modulation mode is then subtracted from the measured SINAD level to obtain a first noise level. In the event the first noise level is less than a noise level required to achieve an acceptable error rate in a next modulation mode, a second signal is transmitted over the selected channel using the next modulation mode.

A wireless communication system is comprised of multiple radio access networks—RANs—which at least partly share the same frequency spectrum. Each RAN is provided with a gateway—GW—(GW1, GW2, GW3) for managing the network. Spectrum sharing in the system is achieved through a hierarchy of processes including long-term—LT—spectrum assignment, short-term—ST—spectrum assignment, and dynamic channel allocation, the latter process assigning sub-channels to base stations (BS1, . . . BS5; BS6, . . . BS10; BS11, . . . BS16) in each RAN. However, so-called “red” sub-channels (subject to interference) are liable to arise.

The present invention is directed to a dynamic channel selector for use with a wireless local area network and a method of selecting a channel therein. In one embodiment, the dynamic channel selector includes a channel quality subsystem that monitors a signal quality of a signal traversing a first channel of the wireless local area network and a noise level of the first channel. The dynamic channel selector also includes an interference mitigation subsystem, coupled to the channel quality subsystem, that selects a second channel of the wireless local area network as a function of the signal quality of the signal traversing the first channel and the noise level of the first channel.

A communication method and apparatus for coordinated multi-point (CoMP) transmission, is provided. Sizes of codebooks for a plurality of base stations may be adjusted based on a status of channels between a target terminal and a plurality of base stations. The terminal feeds back, to at least one of the plurality of base stations, channel direction information (CDI) including a number of bits of feedback.

A dynamic channel allocation method and system for use in a wireless network operates by monitoring at least the allocated channel allocated to a particular network node to generate one or more channel metrics relating to radio conditions on the channel. The metrics generated are Received signal power, signal to noise ratio of transmissions on the network and long-term mean square of the equaliser error used in each terminal. The generated metrics are communicated back to the cell access point or the network control server over a signalling channel, and a new frequency is allocated to the cell if it is determined from the metrics that the presently allocated channel is suffering interference. The signalling channel is preferably an ATM VPI/VCI pair, such that signalling messages are transmitted as ATM cells which can be communicated across the wireless channel using the sane signalling frame as is used for payload cells.

Methods, systems, and devices are described for wireless communications at a wireless device. A wireless device may adaptively select a parity check matrix to increase the reliability of signal transmission by adapting to different channel statistics and channel types (e.g., erasure channels, channels with additive white Gaussian noise, and channels with discrete or continuous alphabets). For example, polarization codes (i.e., codes based on rows of a polarization matrix) may be used to construct parity check matrices “on-the-fly” given an estimation of dynamic channel conditions or diverse channel structures. The channel may be decomposed into polarized sub-channels corresponding to the polarization codes, and mutual information profiles may be determined for each of the polarized sub-channels. The parity check matrix corresponding to the polarization codes may be constructed based on the mutual information profile of all polarized sub-channels. The wireless device may encode or decode data based on the constructed parity check matrix.

Dynamic allocation of communication channels among communication units (CU) in a communications system. Dynamic channel allocation employs a reservation set for reserving channels and an allocation set corresponding to the reservation set for receiving allocated channels. The reservation set and the allocation set are changed dynamically as a function of network parameters to control the dynamic channel operation. Reservation set information is broadcast downlink to multiple users to reserve an allocation set of uplink radio resources for specific ones of the users. The system uses a modification of the packet data channel (PDCH) of a GPRS/EGPRS or EDGE system which employs an Uplink Status Flag (USF) on each PDCH downlink radio block. The downlink reservation set information is commonly received by all users in the group of users. Allocation delay, bandwidth efficiency and other system parameters are optimized.

The invention relates to the field of wireless communications and more specifically to an high quality, low power wireless audio system. More specifically, the invention comprises an audio source for receiving audio signals (e.g. music) and audio status information (e.g. song title) from a first external device (e.g. an MP3 player) and transmitting the audio signals and the audio status information over a wireless connection; and at least one audio sink for receiving the audio signals and said audio status information from the audio source and communicating the audio signals and the audio status information to a second external device (e.g. headphones), wherein a specified one of the at least one audio sink receives audio control information (e.g. pause) from the second external device and transmits said audio control information to said audio source via said wireless connection. Among other features, the wireless audio system of the present invention incorporates dynamic channel selection as well as dynamic adjustment of the transmission interval to ensure enhanced audio quality using the lowest possible power.

A disturbance detection and fast re-train method and apparatus configured for use in a multi-channel communication is disclosed. During data communication disturbance detection occurs by monitoring error rates or other factors, such as crosstalk profiles. Upon detection of a disturbance, the system generates and transmits a line upset condition signal to an opposing terminal and monitors for a similar response from the opposing terminal. Channels which fail to convey such signals may be switch out of service. The signals received via the channels may be utilized as training signals to thereby yield a new crosstalk profile. The new crosstalk profile is processed to establish one or more new multiple input, multiple output filter coefficients, bit loading settings, and gain level settings. These new settings may exchanged with the opposing terminal. In addition, channels which, although transporting signals, yield CRC error rates over a pre-determined threshold, are removed from service.

Provided is a method for dynamic resource allocation of uplink and downlink in an OFDMA/TDD cellular system. The method for dynamic resource allocation of uplink in an OFDMA/TDD cellular system includes the steps of determining the number of sub-channels which can be allocated to each user through an FLR algorithm; performing channel allocation for a first frame through a round-robin algorithm in which channel information is not needed; performing dynamic channel allocation for a next frame through uplink channel information measured by uplink channel sounding; and performing power control. The method for dynamic resource allocation of downlink in an OFDMA/TDD cellular system includes the steps of selecting a user through a GPF algorithm; performing dynamic channel allocation through an ASA algorithm so as to perform a FASA algorithm for obtaining a multiuser diversity gain; and performing dynamic power allocation through an improved CHC algorithm, in consideration of a data rate provided to each user and a channel state.

The present invention protocol offers guaranteed Quality of Service (QoS) for a predetermined number of circuits in a highly dynamic, scalable network. The present invention protocol employs a Time Division Multiple Access (TDMA) reservation scheme to transmit deterministic data (e.g., image data) to a destination, while utilizing a Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) contention scheme to support non-deterministic data traffic. The protocol operates over a link-state based routing protocol that reliably floods routing and resource reservation information to the nodes in the network. Moreover, the present invention capitalizes on certain properties of a radio, such as a RAKE type receiver, to enable simultaneous re-transmissions of resource and route reservation information to constructively interfere and enhance the strength and range of the signal.

The method includes steps: determining assignable dynamic time slot resources and fixed time slot resources in frame structure of communication system; carrying out statistics for demanding of up going and down going bandwidths on small zone or cluster of small zone in a period of time preset; based on result of statistics, calculating parameters of reflecting demand relation between up going and down going bandwidths; based on the said parameters, allotting assignable dynamic time slot resources for up going and down going bandwidths. The invention realizes dynamic channel allocation at slow speed in TD_SCDMA.

Apparatus, systems, and methods disclosed herein operate to calibrate path loss parameters corresponding to a communication channel between wireless stations, including a path loss exponent. A time-of-flight (TOF) associated with packet transmissions traversing a path between a first wireless station and a second wireless station is measured. A path length D1 corresponding to the path is calculated from the TOF measurements. One or more received signal strength (RSS) measurements corresponding to the packet transmissions are then made at the first wireless station. The path loss exponent associated with the path is calculated from D1 and the RSS measurements. Some embodiments may also measure RSS values associated with transmissions from a third wireless station. The latter measurements may be used in conjunction with the previously-determined path loss exponent to derive an unknown transmission path length between the first and third wireless stations. The latter path length may be used together with other known station geometry to determine the coordinate position of the first wireless station.