85results about How to "Improve link performance" patented technology

A free-space adaptive optical laser communication system having signal transmission and reception channels at all terminals in the communication system, wherein wavefront sensing (WFS) and wavefront correction mechanisms are employed along signal transmission and reception channels of all terminals in the communication system (i.e. adaptive optics) to improve the condition of the laser beam at the receiver (i.e. reduce the size of the spot a the detector plane). in the illustrative embodiment, the WFS mechanisms employ a novel WFS control process, in which active updating of reference positions and subaperture locations on the wavefront sensor. These WFS mechanism can be used in diverse application environments, including but not limited to FSO laser communication systems.

A wireless local area network (WLAN) includes mobile devices that are allowed to transfer wireless connections between WLAN subnets or channels having different access points. The access points connect to a central controller or roaming server that supports seamless hand-offs of mobile devices from one access point to another access point. The roaming server supports the reassignment of session data parameters from one access point to another (e.g., access point address spoofing) so that the mobile device can use the same parameters for communicating to a new access point. The roaming server also supports the seamless handoff of a mobile device from one access point to another by using a master-slave switch technique across two piconets. The roaming server also facilitates the control of access points by establishing a host controller interface and wireless protocol stack in the roaming server and another, complementary wireless protocol stack in the access point. The roaming server then encapsulates host controller commands in a packet based network protocol used for communication between the roaming server and the access points.

A system, method, and computer program product for allocating resources to a communication channel between a transmitter and a receiver are disclosed. The receiver implements a procedure that instructs the transmitter to utilize the maximum available bandwidth, consistent with maintaining satisfactory communication channel performance. When the performance of the communication channel degrades, the receiver measures the strength of a communication signal received from the transmitter. If the communication signal strength satisfies a threshold, then the bandwidth dedicated to the communication channel may be decreased, and at least one of the number of bits per symbol and coding rate may be increased. By contrast, if the communication signal strength fails to satisfy a threshold, then the transmitter may increase the transmission power and/or reduce the user rate of the communication link.

A method and apparatus of controlling transmit power in a wireless communication system is provided. A wireless apparatus selects one transmit mode among a plurality of transmit modes, and determines the transmit power on the basis of the selected transmit mode. The wireless apparatus transmits an uplink channel by using the transmit power.

A method enables the use of a secondary pilot signal and a secondary antenna(s) in the forward link of a CDMA-based cellular network employing a slotted transmission scheme with a time-multiplexed primary pilot signal, with backwards compatibility. The forward link is divided into a number of time slots. For communications with “legacy” mobile stations that expect transmissions from a single, primary antenna (and that expect a single, primary pilot signal), during some of the time slots, only the primary antenna is used for transmissions, including transmitting the primary pilot signal. Neither the secondary pilot channel nor any other signals from the secondary antenna are transmitted. During the remaining time slots: (i) the primary pilot signal is transmitted from the primary antenna, and the secondary pilot signal is transmitted from the secondary antenna, but at different times; and (ii) data meant for the legacy mobile stations is not transmitted.

Reverse link reception and reverse link capacity are improved at a multi-sector radio base station (RBS) by forcing always-softer reverse link handoff conditions for mobile stations served by the RBS. Whenever a serving sector reverse link is assigned to a mobile station at the RBS, one or more additional reverse links are assigned to it from remaining sectors of the RBS. Such assignments are made irrespective of whether those sectors are, or could be, used to serve the mobile station on the forward link. The RBS improves its reception of the mobile station's reverse link transmissions by combining signals from all of the assigned reverse links. With improved reception, mobile stations can be commanded or configured to reduce their reverse link transmit power, thereby reducing reverse link interference and increasing reverse link capacity. Always-softer handoff may not be forced unless the mobile station has a reverse supplemental channel, since the use of such channels makes interference reduction particularly beneficial.

The invention provides an eNB handover method in a heterogeneous network and an eNB. The method comprises: after a target eNB receives a handover request message from a first eNB, access control is executed; whether connection to a second eNB by UE is kept after the access of the UE is determined; if so, an assisting request message is sent to the second eNB and thus the second eNB is requested to assist the target eNB in providing a dual-connection service for the UE; and after a reply message from the second eNB is obtained, a handover request confirmation message is returned to the first eNB. According to the invention, when a main service eNB of the UE carries out switch, performances of the link between the UE and the second eNB can be improved; the state of the link between the UE and the connected second eNB can be determined; the possibility of interruption can be reduced or rapid restoration from the interruption can be realized; the performance and throughput capacity for data transmission by the UE can be improved effectively; the using efficiency of wireless resources is enhanced; and the control plane signaling is reduced.

The link quality reporting method includes measuring link quality for received radio blocks, and if there is a modulation scheme with a largest number of radio blocks, reporting link quality for the modulation scheme, and if there is a plurality of schemes with the same number of radio blocks, reporting link quality for a modulation scheme selected using a predetermined method. Performance deterioration can be minimized in a link adaptation process.

A transmission/reception apparatus for transmitting packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system. The apparatus includes a transmission module for generating a frame of an OFDM symbol including pilot tones using the packet data, and transmitting the frame to a wireless network; and a controller for changing at least one of a Pilot-to-Data Ratio (PDR) of the pilot tones and a density of the pilot tones based on a length of the frame. The reception apparatus includes a reception module for receiving a frame of an OFDM symbol including pilot tones from a wireless network, extracting the pilot tone from the received frame, performing channel estimation thereon, and demodulating the packet data; and a controller for receiving at least one of a PDR of the pilot tone and a density of the pilot tone, both of which are in proportion to a length of the frame, and controlling the reception module so that the channel estimation is performed, based on the received information.

The invention discloses a relay and antenna joint selection method for a full-duplex bidirectional relay system. The method comprises the following steps: calculating the signal-to-noise ratios of relay nodes relative to two source nodes, and selecting the minimum signal-to-noise ratios as the effective signal-to-noise ratios of the relay nodes; screening out the relay node corresponding to the maximum signal-to-noise ratio, and taking the relay node as an optimal relay node; calculating the signal-to-noise ratios of the two source nodes based on different antenna configuration modes, and screening out the maximum of the signal-to-noise ratios of the two source nodes and the optimal relay node relative to different antenna configuration modes; and setting the antenna configuration mode corresponding to the maximum of the signal-to-noise ratios as an optimal antenna configuration mode. The relay and antenna joint selection method for a full-duplex bidirectional relay system is based on joint selection of an optimal relay and an optimal antenna configuration mode. Communication system link performance optimization is realized, and the achievable rate and spectrum efficiency of the communication system are improved.

Embodiments include systems and methods for improving link performance and tracking capability of a baud-rate clock data recovery (CDR) system using transition pattern detection. For example, a multi-level signal is received via a data channel and converted to a pseudo-NRZ signal. CDR early/late voting can be derived from the converted (baud-rate) pseudo-NRZ signal and from error signals from the received PAM4 signal, and the voting can be implemented with different phase error detector (PED) functional approaches. Different approaches can yield different CDR performance characteristics and can tend to favor different PAM4 transition patterns. Embodiments can identify jittery patterns for a particular CDR implementation and can add features to the CDR to filter out those patterns from being used for CDR early/late voting.

The link quality reporting method includes measuring link quality for received radio blocks, and if there is a modulation scheme with a largest number of radio blocks, reporting link quality for the modulation scheme, and if there is a plurality of schemes with the same number of radio blocks, reporting link quality for a modulation scheme selected using a predetermined method. Performance deterioration can be minimized in a link adaptation process.

The invention discloses an interference noise estimation and an interference inhibition method and a corresponding system. In an interference inhibition zone, when one borne dataflow is subjected to interference noise estimation with the method, the method comprises the following steps: for each pilot frequency subcarrier corresponding to the dataflow, calculating to obtain the interference noise covariance matrix of the position of the pilot frequency subcarrier according to a pilot frequency signal sent by a transmitting end on the pilot frequency subcarrier, a receiving signal on the pilot frequency subcarrier and a channel coefficient estimation value of the position of the pilot frequency subcarrier; for each data subcarrier corresponding to the dataflow, taking the weighted average of the interference noise covariance matrix of the position of each pilot frequency subcarrier corresponding to the dataflow as a first interference noise covariance matrix; and taking a result obtained by carrying out diagonal loading on the first interference noise covariance matrix as a second interference noise covariance matrix. When an adjacent cell has same-frequency interference, the interface noise can be accurately estimated with the interference noise estimation and interference inhibition method, and the interference inhibition result is improved.

The invention discloses a pilot frequency processing method, which comprises the following steps: grouping antennae of an emission source performing network-level cooperation to obtain a plurality of antenna groups, wherein the number of the antenna groups is equal to that of emission antennae supported by service cells in a non-cooperative state; configuring the pilot frequencies of the plurality of the antenna groups so that the pilot frequencies between the antenna groups are orthogonal with each other; and the pilot frequency patterns of the plurality of the antenna groups are in one-to-one correspondence with that of the emission antennae supported by the cells in the non-cooperative state. By using the method, the good compatibility of a cooperative mode and a non-cooperative mode can be achieved, the interferences between the cells are inhibited effectively, and simultaneously all the antennae can be used sufficiently to perform data transmission, and the capacity, the throughput rate and the link performance of a system are improved.

Provided are a bearing device for a wheel, in which circumferential play is reduced, which provides excellent workability in connection between a hub ring and an outer joint member of a constant velocity universal joint, in which fitting between the hub ring and the outer joint member of the constant velocity universal joint is stable, and which has excellent strength, and an axle module using the bearing device. An axially extending projection is formed on either of the outer diameter surface of a shaft section of the outer joint member and the inner diameter surface of a hole of the hub ring. The projection is press-fitted to the other in the axial direction to form a recess in the other by the press-fitting. By this, a recess/projection fit structure is formed, in which the entire regions of those portions of the projection and the recess at which they are fitted to each other are in intimate contact with each other. The hardness of at least that portion of the projection at which the press-fit starts is higher than that of a portion where the recess is formed. The difference in hardness in HRC is 20 or more.

The invention discloses a method for configuring space diversity of an ePDCCH. The method comprises the following steps: REs of each eREG take one RE as the particle size to alternatively use one of NAP antenna ports; REs in each PRB pair are respectively mapped in one fixed AP. The invention also discloses a method of constructing local eCCEs, and a method of constructing distributed eCCEs. The invention further discloses equipments corresponding to the three methods. According to the invention, the space diversity performance of the distributed ePDCCHs can be improved, and the number of REs of the local eCCEs and the distributed eCCEs can be averaged, thereby ensuring the consistence or approaching of link path performance.

The invention relates to the field of building materials and the field of water conservancy construction, in particular to various clay, weathered granite soil and hoggin soil. Soil at construction sites of artificial lakes, artificial canals and irrigation channels is used as main materials, special macromolecular coagulant, limestone or gravel sandy soil are mixed with Portland cement, and compression molding equipment is used for once forming of seepage-proofing bricks. The main materials include, by weight, 0.02 part of coagulant, 0.2 part of glass fiber chopped strands (biological straws), 70-80 parts of soil, 5-6 parts of cement and 10-15 parts of gravels (weathered granite soil). In terms of performance, the seepage-proofing bricks made by the method have sufficient compressive strength and shear resistance and can meet the normal artificial water conservancy seepage proofing requirements; in terms of process, operation is simple and easy and soil is taken in situ; and in terms of cost, the cost is at least 50% lower than that of cement mortar seepage proofing, soil needed to be removed at the construction sites is treated, construction cost is reduced, and construction cycle is shortened.

The invention discloses a superconducting link system, comprising a network adapter device, a network protector, an ultralow temperature vacuum multi-channel combined type Dewar, a high temperature superconduction wave filter, an ultralow temperature low-noise amplifier (LNA), a refrigerating system, a high-stability power supply system and an superconducting link intelligent monitoring system, wherein the high temperature superconduction wave filter and the ultralow temperature LNA are arranged in the ultralow temperature vacuum multi-channel combined type Dewar and operate in high vacuum environment with ultralow temperature and long-term holding pressure. In the superconducting link system, a brand new scientific overall structure design and a special manufacturing technology are adopted, thus the superconducting link system has extremely high out-band interference resisting capability and intermodulation interference reducing capacity, and can effectively reduce background noise of the system and improve gains for useful signals, thereby greatly enhancing the performance of a receiving link from an antenna to the output end of a receiver of a master station, greatly improving communication coverage, quality, capacity, user satisfaction, low-carbon and environmental-friendly network environment, and greatly increasing resource utilization rate of frequency spectrum and system equipment, return on investment, construction speed and the like.

The invention provides a method and device for cyclic redundancy check. The method includes the steps: determining a load portion, wherein the load portion includes at least one information field, andthe at least one information field is used for carrying information bits; determining an input bit for generating a cyclic redundancy check CRC bit, wherein the input bit includes the information bits carried in part or all of the information field of at least one information field; according to the input bit, generating a target CRC bit; and generating control information including the load portion and the target CRC bit. The method for cyclic redundancy check avoids the situation that a receiving end device considers that the control information transmission is in error when the informationbit transmission is error-free and the filling bit transmission error occurs, or avoids the error in the partial information bit transmission while the important information bits have no error, and when part of information bit receiving end with the transmission error can be tolerated, the receiving end device considers that the control information transmission error occurs, so that the link performance of the communication system is improved.

A method is provided wherein a base station and at least one further base station are assigned to a cooperation area, wherein a user equipment is served by the base station. The method comprises determining, by the base station), whether all user data of the user equipment being required for a precoding coordinated multipoint transmission is received by each of the base station and the at least one further base station, selecting a transmission mode, wherein the transmission mode is based, if all user data of the user equipment being required for a precoding coordinated multipoint transmission is received by each of the base station and the at least one further base station, on precoding coordinated multipoint transmission, or else, on an interference reducing transmission, and configuring, by the base station, the communication channel between the base station and the user equipment based on the selected transmission mode.