摘要:
A battery is charged by first charging the battery at a constant current during a first time interval, and then charging the battery at a varying current during a second time interval. The battery can be a lithium-ion battery, and the charging uses a kinetic model. The kinetic model models the battery having an indiffused well having a capacity c, and a difused well having a capacity 1−c, and the indiffused well is filled directly by the current, and the diffused well is filled only from the indiffused well via a valve with constant inductance.
摘要:
Embodiments of the invention facilitate providing wireless links with longer link ranges and/or better suppression of interference than can be provided by the integrated antennas of a typical wireless network node. While, in some cases, it is possible to install intermediate wireless network nodes to hop through long expanses between distant wireless network nodes, it is desirable for distantly spaced wireless network nodes to reach one another through a single transit link (i.e. one hop). This approach is preferable because a single transit link is capable of higher data rates and better interference suppression than multi-hop transit links. The present invention provides methods and apparatus for enhancing the link range achievable by typical wireless network nodes so that distantly spaced wireless network nodes are able to communicate with one another using only a single-transit link.
摘要:
A method for detecting unbalance in a 3-phase voltage signal includes sampling the signal over an observation widow to determine a set of observations, and detecting the unbalance of the signal based on a probability density function (pdf) of the set of observations.
摘要:
A device includes a source for transmitting an electronic charge through a conduction path; a drain for receiving the electronic charge; a stack for providing at least part of the conduction path; and a gate operatively connected to the stack for controlling a conduction of the electronic charge. The stack includes an insulator layer, an N-polar layer and a barrier layer selected such that, during an operation of the device, the conduction path formed in the N-polar layer includes a two-dimensional electron gas (2DEG) channel and an inversion carrier channel.
摘要:
At least one parameter of a signal is determined, wherein the signal is a sinusoidal signal including noise, wherein the parameter includes at least one of a frequency of the signal, and an angle of a phase of the signal. The frequency of the signal is determined iteratively based on a linear relationship among the frequency of the signal, samples of the noise, and samples of the signal using a statistical correlation among the samples of the noise. During a current iteration the statistical correlation is updated based on the frequency of the signal determined during a previous iteration, and the samples of the signal are updated with values of the signal during a current period of time.
摘要:
A method estimates parameters of 3-phase voltage signals to synchronize a power grid in a presence of a voltage unbalance by transforming the 3-phase voltage signals to αβ-reference signals using a Clark transformation matrix, and estimating sinusoidal signals and corresponding quadrature signals of the αβ-reference signals using an extended Kalman filter, and determining a phase angle of a positive sequence based on a relationship of the phase angle to the estimated the sinusoidal signals.
摘要:
Packets in a multi-hop wireless network are routed based on the available link throughputs, network node congestion and the connectivity of the network in a manner that minimizes the use of radio resources and minimizes delay for packets in multi-hop system. The routing method also avoids congestion in the access network, especially near the network access points as provided by network access nodes. Each wireless network node maintains a link table for storing link conditions and associated route costs. Packets are routed according to the low cost route. Subsequent wireless network nodes evaluate whether a lower cost route is available and, if so, route the data packet according to the lower cost route. Every wireless network node transmits the data packet, a specified route and a time stamp indicated a time of the last data entry in the link table that was used to calculate the low cost route.
摘要:
Protocols for OFDM/OFDMA/SC-FDMA based wireless networks provide adaptive inter-cell interference management without explicit spectrum or frequency planning. Base stations and mobile stations acquire information about subcarrier allocation from a handoff protocol. The mobile stations can also acquire this information using cognitive sensing. Cognitive sensing can be rewarded by the base station. Using this information, subcarriers can be allocated randomly, with blind optimization, or by joint optimization. The stations can use game theory to select among the different optimization strategies.
摘要:
A method for allocating resources in an orthogonal frequency division multiple access (OFDMA) network, where each cell in the network has a center region and an edge region. The cell center region uses a frequency band orthogonal to the frequency band used by the cell edge region. The frequency band is made up of resource blocks (RBs) or non-overlapping sets of subcarriers. Upon availability of cell-center RBs, cell-center user equipment (UEs) are assigned resource blocks. A fixed number of cell edge regions from a few adjacent cells form a cluster, and only the cell edge regions with the highest achievable throughput rate within each cluster gets to transmit in a given scheduling instance.
摘要:
A method and system enables and improves performance of hybrid automatic repeat request (HARQ) operations on channels between stations of an orthogonal frequency division multiple access (OFDMA) wireless communication network. There, the number of parallel HARQ channels is increased adaptively, and one connection identifier is used to unambiguously identify a set of MAC protocol data units (MPDUs) communicated over parallel HARQ channels. A sequence number is used to avoid out-of-order MPDU delivery when MPDUs are transmitted over parallel HARQ channels. The MPDUs can be concatenated or encapsulated. The maximum number of the parallel HARQ channels can be increased to 256, and can be negotiated when a station enters or re-enters the network.