7271results about "Transmission control/equalising" patented technology

Exploiting the substantive reciprocity of internode channel responses through dynamic, adaptive modification of receive and transmit weights, enables locally enabled global optimization of a multipoint, wireless electromagnetic communications network of communication nodes. Each diversity-channel-capable node uses computationally efficient exploitation of pilot tone data and diversity-adaptive signal processing of the weightings and the signal to further convey optimization and channel information which promote local and thereby network-global efficiency. The preferred embodiment performs complex digital signal manipulation that includes a linear combining and linear distribution of the transmit and receive weights, the generation of piloting signals containing origination and destination node information, as well as interference-avoiding pseudorandom delay timing, and both symbol and multitione encoding, to gain the benefit of substantive orthogonality at the physical level without requiring actual substantive orthogonality at the physical level.

A method called the evolvable interference management (EIM) method is disclosed in this patent for avoiding interference and collision and increasing network throughput and energy efficiency in wireless networks. EIM employs sensitive CSMA / CA, patching approaches, interference engineering, differentiated multichannel, detached dialogues, and / or spread spectrum techniques to solve the interference and QoS problems. EIM-based protocols can considerably increase network throughput and QoS differentiation capability as compared to IEEE 802.11e in multihop networking environments. Due to the improvements achievable by EIM, the techniques and mechanisms presented in this application may be applied to obtain an extension to IEEE 802.11 to better support differentiated service and power control in ad hoc networks and multihop wireless LANs. New protocols may also be designed based on EIM.

A method adapts scheduling priorities in a CDMA wireless communications system to conserve battery power in mobile terminals operating within the system. A base station, within the system, receives battery power level information and other setup information from mobile terminals operating within the service area of the base station during call setup procedures. Based on the battery power level information and other setup information, the base station adapts scheduling priorities for the mobile terminals to expedite wireless transmissions from those mobile terminals reporting low battery power levels. The base station schedules the transmissions from low battery power mobile stations to be clustered together in a low-power time slot which is separate in time from the scheduled transmissions from high battery power mobile stations. The base station transmits a power control message to the low battery power mobile stations, to reduce the transmission power required for those mobile stations during the low-power time slot.

Exploiting the substantive reciprocity of internode channel responses through dynamic, adaptive modification of receive and transmit weights, enables locally enabled global optimization of a multipoint, wireless electromagnetic communications network of communication nodes. Each diversity-channel-capable node uses computationally efficient exploitation of pilot tone data and diversity-adaptive signal processing of the weightings and the signal to further convey optimization and channel information which promote local and thereby network-global efficiency. The preferred embodiment performs complex digital signal manipulation that includes a linear combining and linear distribution of the transmit and receive weights, the generation of piloting signals containing origination and destination node information, as well as interference-avoiding pseudorandom delay timing, and both symbol and multitone encoding, to gain the benefit of substantive orthogonality at the physical level without requiring actual substantive orthogonality at the physical level.

Coexistence gaps may permit one radio access technology (RAT) to coexists with another RAT by providing period in which one RAT may be silent and another may transmit. Methods may account for the RAT traffic and for the presence of other secondary users in a channel. Methods may be provided to dynamically change the parameters of a coexistence gap pattern, such as the duty cycle, to adapt to both the RAT traffic and the presence of other secondary users. Methods may include PHY methods, such as synchronization signal (PSS / SSS) based, MIB based, and PDCCH based, MAC CE based methods, and RRC Methods. Measurements may be provided to detect the presence of secondary users, and may include reporting of interference measured during ON and OFF durations, and detection of secondary users based on interference and RSRP / RSRQ measurements.

In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. For example, the loading conditions of the cells can be detected, and the resources can be reallocated and / or the reuse scheme can be redefined. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users. Data transmissions can be scheduled based on user priorities, some fairness criteria, system requirements, and other factors. Users are assigned to available channels based on a number of channel assignment schemes. Channel metrics are also provided, which can be used to prioritize users and for channel assignments.

A pipelined digital data receiver for a cable TV headend which is capable of receiving DOCSIS 1.0 or 1.1 or advanced PHY TDMA or SCDMA bursts having programmable symbol rates and programmable modulation types as well as a host of other burst parameters such at Trellis code modulation on or off, scrambling on or off, various values for Reed-Solomon T number and codeword length. The receiver has an RF section to filter and digitize incoming RF signals. It also has an input section to detect impulse noise and do match filtering and despread SCDMA bursts. A timing recovery section recovers the symbol clock and detects the start of bursts and collisions. A rotational amplifier and equalizer calculate and track gain, phase and frequency offsets and correct symbols and calculates equalization coefficients. A decoder section decodes TCM and non TCM bursts, and a Reed-Solomon decoder section reconstructs RS codewords and uses them to error correct the payload data.

In a wireless communication network providing voice and data services, one or more entities in the network, such as a base station controller and / or radio base station, can be configured to reduce data services overhead responsive to detecting a congestion condition, thereby increasing the availability of one or more network resources for voice services. In one or more exemplary embodiments, one or more current data services users are targeted for modification of their ongoing data services to effect the reduction in data services overhead. Modifications can include, but are not limited to, any one or more of the following: forward or reverse link data rate reductions, and shifting of forward or reverse link traffic from dedicated user channels to shared user channels. Targeting of users for service modification can be based on reported channel quality information. For example, users reporting poor radio conditions can be targeted first for service modifications.

Techniques for adjusting transmit power to mitigate both intra-sector interference to a serving base station and inter-sector interference to neighbor base stations are described. The amount of inter-sector interference that a terminal may cause may be roughly estimated based on the total interference observed by each neighbor base station, channel gains for the serving and neighbor base stations, and the current transmit power level. The transmit power may be decreased if high interference is observed by a neighbor base station and increased otherwise. The transmit power may be adjusted by a larger amount and / or more frequently if the terminal is located closer to the neighbor base station observing high interference and / or if the current transmit power level is higher, and vice versa. The intra-sector interference is maintained within an acceptable level by limiting a received SNR for the terminal to be within a range of allowable SNRs.

An adaptive multicarrier wireless communication system, apparatus and associated methods are generally disclosed herein.

Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a “beam-forming” transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a “multi-mode” transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment.

An apparatus and process for allocating carriers in a multi-carrier system is described. In one embodiment, the process comprises determining a location of a subscriber with respect to a base station, selecting carriers from a band of carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station, and allocating selected carriers to the subscriber.

A system and method are described for compensating for frequency and phase offsets in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”). For example, a method according to one embodiment of the invention comprises: transmitting a training signal from each antenna of a base station to one or each of a plurality of wireless client devices, one or each of the client devices analyzing each training signal to generate frequency offset compensation data, and receiving the frequency offset compensation data at the base station; computing MU-MAS precoder weights based on the frequency offset compensation data to pre-cancel the frequency offset at the transmitter; precoding training signal using the MU-MAS precoder weights to generate precoded training signals for each antenna of the base station; transmitting the precoded training signal from each antenna of a base station to each of a plurality of wireless client devices, each of the client devices analyzing each training signal to generate channel characterization data, and receiving the channel characterization data at the base station; computing a plurality of MU-MAS precoder weights based on the channel characterization data, the MU-MAS precoder weights calculated to pre-cancel frequency and phase offset and / or inter-user interference; precoding data using the MU-MAS precoder weights to generate precoded data signals for each antenna of the base station; and transmitting the precoded data signals through each antenna of the base station to each respective client device.

The present invention provides novel systems and methods for improving the voice quality of wireless-to-wireless calls or wireless-to-fixed terminal calls. This disclosure describes methods and apparatuses to determine and control the quality of service objectives in a telecommunication network involving at least one wireless terminal.

A true cross-layer integration of functions is provided on several protocol layers within a network, thus providing a unified approach to Quality of Service (QoS) provisioning in a multihop network. In the unified approach, connections are preferably determined by integrated optimization of a given objective function with respect to connection parameters on at least three protocol layers within the network. Preferably, the optimization involves routing (path selection), channel access as well as adaptation of physical link parameters. By incorporating physical connection parameters together with properly designed constraints, the issue of interference can be carefully considered. It is thereby possible to determine connection parameters that ensure substantially non-interfering communication with respect to existing connections as well as the new connection.

The present invention relates to wireless networks using relaying. In the method according to the present invention of performing communication in a two-hop wireless communication network, a transmitter 210, a receiver 220 and at least one relay station 215 are engaged in a communication session. The relay station 215 forwards signals from a first link between the transmitter 210 and the relay station 215 to a second link between the relay stations 215 and the receiver 220. The forwarding performed by the at least one relay station 215 is adapted as a response to estimated radio channel characteristics of at least the first link. Preferably the forwarding is adapted as a response to estimated radio channel characteristics of both the first and second link.

A method and apparatus for wireless communication are described. In one embodiment, a method for communicating with a subscriber comprises transmitting orthogonal frequency domain multiplexing (OFDM) signals to the subscriber, and receiving direct-sequence spread spectrum (DSSS) signals from the subscriber.

There is provided a method for improving an allocation of resources, i.e., frequency and power, to terrestrial services and satellite services that use a same frequency band. The method includes determining a demand (DS) for a resource by users of a satellite system, determining a demand (DT) for the resource by users of a terrestrial system, and allocating the resource between the satellite system and the terrestrial system based on a ratio of DS to DT.

A network is described. In one embodiment, the network comprises multiple subscriber units to communicate with the base station using an orthogonal frequency-division multiple-access (OFDMA) protocol, and a base station. The base-station includes a memory unit to store broadband spatial signature vectors associated with each subscriber and traffic channel allocation logic. The vectors are a function of frequency. The traffic channel allocation logic allocates OFDMA channels using the broadband spatial signature vectors of the subscribers.

A method and system for dynamic soft handoff resource allocation in a wireless communications network includes determining a wireless path characteristic individually for each path of a macro diversity connection between a mobile device and a plurality of wireless sites. Wireless resources are allocated for the macro diversity connection between the mobile device and the wireless sites based on the wireless path characteristic. The wireless path characteristic includes a location-based characteristic, a congestion-based characteristic, a subscriber-based characteristic and / or a performance-based characteristic.

With the addition of high-speed data traffic to traditional CDMA cellular networks, there is a need to efficiently utilize system capacity so that the quality of service of existing voice and low-speed data users is maintained while new high-speed data users are added to the network. Methods and systems are presented that control allocation of power to users, quality of service requirements, and / or user activity levels to enhance capacity utilization. These methods and systems are based on a method for estimating the capacity of a CDMA carrier with both voice and data users using an interference-based analysis of the reverse link. In particular, the methods enhance capacity utilization in a multi-code CDMA network architecture, in which several codes are allocated to a single high-speed data user for parallel transmission.

Systems and methods for enabling a mobile user to notify an automated monitoring system of an emergency situation are provided. The automated monitoring system may be configured for monitoring and controlling a plurality of remote devices and may comprise a site controller in communication with the plurality of remote devices via a plurality of transceivers defining a wireless communication network and in communication with a host computer via a wide area network. Briefly described, one such method comprises the steps of: receiving notification that the mobile user desires to initiate transmission of an emergency message to the site controller; determining the identity of the mobile user; and providing an emergency message over the wireless communication network for delivery to the site controller, the emergency message indicating the identity of the mobile user.

MIMO transmission methods are applied to communicaiton systems in which a transmitter has more than one transmit antenna and a receiver has more than one receive antenna. Information to be transmitted is divided into a plurality of subsignals according to the number of used transmit antennas and each subsignal is processed separately before it is emitted by the respective transmit antenna. In the receiver the different receive signals are processed thus that subsignals are detected and decoded and the contribution of each detected and decoded subsignal is subtracted from the receive signals and whereby a feedback channel from receiver to transmitter is used to send control information to the transmitter depending on the receive situation. In order to optimize the usage of the MIMO channel the invention proposes the in the receiver the link quality of each subsignal is determined and information of each subsignal is transmitted to the receiver via the feedback channel and that in the transmitter properties of the subsignals are controlled by the link quality information.

A method for transmitting and receiving channel state information (CSI) periodically and aperiodically is disclosed. The method for aperiodically transmitting channel state information (CSI) by a terminal includes receiving an indicator requesting a channel state information report of a downlink channel from a base station over a downlink control channel, and aperiodically transmitting the channel state information (CSI) to the base station over a physical uplink shared channel (PUSCH) upon receiving the indicator from the base station.

Two-way (full-duplex) wireless communications. Various embodiments measure interference channels and provide for interference cancellation in both analog and digital domains to mitigate self-interference. The system supports multiple clients wherein new clients can join the network asynchronously, and also supports Multiple-Input Multiple-Output (MIMO) antennas.

The present invention relates to relay supported wireless communication to enhance communication performance. In the wireless communication system according to the invention neighboring relay stations are arranged with substantially overlapping coverage. In the method according to the invention mobile stations makes soft association to relay stations. The mobile stations feed back the selection of relay stations and channel quality measures to the base station. The base station adapts the transmission to the relay stations based on each mobile stations reported soft associations and channel quality measures. In this way the control signaling to and from the relay stations can be very limited.

In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users.

A new system and method is described, utilizing a scheduler based on a transmission power consumption calculation and prioritizing algorithm. The system utilizes the (APSD) protocol specified in the 802.11e draft for saving power in wireless local area networks. The system comprises an access point having a priority queue, one or more stations, an APSD frame comprising an association ID for identifying one of the stations and a scheduled wake-up time for the identified station. An algorithm is employed for calculating the total transmission power consumption of downlink data for the stations. The AP originates and transmits to the one or more stations the APSD frame of the scheduled activation delay time. The current data to be transmitted to each station is accessed by the algorithm to determine the total transmission power consumption to each station. A priority queue in the AP is ordered from the lowest to the highest receiving power consumption, assigning the highest priority to the lowest power consumption transmission to minimize total power consumption to the PS stations in the AP queue.

The present invention relates to Random Access Channel (RACH) access apparatus for mobile satellite communication system and method therefor. The method for accessing random access channel (RACH) on satellite system, random access channel (RACH) carrying message from a plurality of mobile stations to the satellite system, the method includes the steps of: receiving preamble and the message, the message successively transmitted with the preamble from the plurality of mobile stations; and transmitting acquisition response signal corresponding to the preamble or the message to the plurality of mobile stations. Accordingly, success of packet reception of satellite system is improved and transmission delay is reduced.

A method is provided for establishing P2P radio connection in wireless communication networks, comprising: the user equipment, as the link probing originator, transmits link probing signals via the allocated direct communication link to another user equipment as the link probing responder, according to the initial probing power provided by the wireless communication system; said another user equipment transmits the ACK message to the link probing originator via the direct communication link when receiving the link probing signals and said link probing signals meet the basic requirement for direct communication; the user equipment, as the link probing originator, monitors the direct communication link, and communicates directly with the link probing responder via the direct communication link after detecting the ACK message from the link probing responder. This method effectively guarantees the procedure of establishing P2P communication between the user equipments in P2P communication course, by utilizing the link probing process of transmitting link probing signals.