47 results about "Channel inversion" patented technology

A bidirectional signal processing method uses parallel transmission of digital transmitted data streams in a multiple input-multiple output system. Related art methods generate high bit error rates mostly in singular transmission channels. For this reason, the rank-adaptive signal processing method provides that the number n_d of active subchannels are varied according to the actual channel behavior in order to effect a robust data transmission even in singular radio channels based on a transmit-side and receive-side channel knowledge and a modification of the data vector by a linear matrix vector multiplication while introducing a factor gamma for limiting the maximum transmit power. The maximum transmit power is then only distributed to the currently activated subchannels so that no transmit power remains unused. Another optimization of the number of subchannels n_d occurs when selecting the modulation and encoding methods. During the optimal rank-adaptation according to the water-filling principle, another power is allocated to each subchannel. Another modulation and encoding method is accordingly selected for each data stream. During the suboptimal rank-adaptation according to the channel inversion principle, all subchannels have the same power whereby enabling the data streams to be modulated and encoded in a common source

A new method is provided for the creation of sub-micron gate electrode structures. A high-k dielectric is used for the gate dielectric, providing increased inversion carrier density without having to resort to aggressive scaling of the thickness of the gate dielectric while at the same time preventing excessive gate leakage current from occurring. Further, air-gap spacers are formed over a stacked gate structure. The gate structure consists of pre-doped polysilicon of polysilicon-germanium, thus maintaining superior control over channel inversion carriers. The vertical field between the gate structure and the channel region of the gate is maximized by the high-k gate dielectric, capacitive coupling between the source/drain regions of the structure and the gate electrode is minimized by the gate spacers that contain an air gap.

A nonvolatile semiconductor memory device for storing data by accumulating charge in a floating gate includes a plurality of MOS transistors sharing the floating gate. In the device, a PMOS is used for coupling during writing and an n-type depletion MOS (DMOS) is used for coupling during erasure. Coupling of channel inversion capacitance by the PMOS is used for writing and coupling of depletion capacitance by the n-type DMOS is used for erasure, thereby increasing the erase speed without increase of area, as compared to a conventional three-transistor nonvolatile memory element.

The invention relates to a recognition method of foreign bodies in a grain pile, which is used for solving the problems of large interference, inaccurate classification and incapability of classifying multiple targets in the prior art. The method comprises the following steps of: firstly positioning a foreign body target in a ground penetrating radar map by utilizing an image processing technology and a Hough transformation method, then carrying out multilayer single-channel inversion on a dielectric constant on the channel where the foreign body target is positioned on the basis of refraction and refection laws, and finally determining the kind of the foreign body according to the dielectric constant subjected to the multilayer single-channel inversion and the corresponding relation of the dielectric constant and the common foreign body to realize the recognition of the foreign body. The method only needs echo amplitude information and does not need echo phase information, so that the algorithm is more easy to realize. Meanwhile, because of the difference of the dielectric constants of different kinds of objects, the method is more accurate for classifying and recognizing the foreign bodies and can simultaneously classify different kinds of foreign bodies in the same area.

The invention relates to a precoding method and a precoding system for eliminating interference. The precoding method comprises a step S1 of detecting values of interference of multiple micro base stations on each user among multiple users of a macro base station, and clustering the multiple micro base stations with values of interference on any user of the multiple users larger than a preset value, in order to form a micro base station group, a step S2 of eliminating inter-user interference through zero-forcing channel inversion conversion and QR decomposition, and a step S3 of eliminating inter-user interference in the micro base station group through lattice reduction conversion and zero-forcing channel inversion conversion. With the technical scheme provided by the invention, the speed of precoding operation is accelerated, the precoding effect is improved, the overall complexity of precoding operation is reduced, and an interference elimination effect is improved.

The system and method optimizes a SNR calculation for a signal received during a downlink burst even in the absence of a node's preferred modulation. This system and method are used in communication systems that include a multi-modulation modem. An adaptation factor is selected whereby its use during portions of the downlink burst, which were not modulated using the preferred modulation, provides the SNR. The selected adaptation factor is used by an equalizer to perform channel inversion to the signal. The system and method can be used in, for example, an FDD or TDD communication system. Such communication systems can be, for example, symmetric, asymmetric, and/or adaptive in their operation.

A nonvolatile semiconductor memory device for storing data by accumulating charge in a floating gate (32) includes: a plurality of MOS transistors (24, 25, 26) sharing the floating gate (32). In the device, a PMOS (24) is used for coupling during writing and an n-type depletion MOS (DMOS) (25) is used for coupling during erasure. Coupling of channel inversion capacitance by the PMOS (24) is used for writing and coupling of depletion capacitance by the n-type DMOS (25) is used for erasure, thereby increasing the erase speed without increase of area, as compared to a conventional three-transistor nonvolatile memory element.

Techniques for processing a data transmission at a transmitter and receiver, which use channel eigen-decomposition, channel inversion, and (optionally) “water-pouring”. At the transmitter, (1) channel eigen-decomposition is performed to determine eigenmodes of a MIMO channel and to derive a first set of steering vectors, (2) channel inversion is performed to derive weights (e.g., one set for each eigenmode) used to minimize ISI distortion, and (3) water-pouring may be performed to derive scaling values indicative of the transmit powers allocated to the eigenmodes. The first set of steering vectors, weights, and scaling values are used to derive a pulse-shaping matrix, which is used to precondition modulation symbols prior to transmission. At the receiver, channel eigen-decomposition is performed to derive a second set of steering vectors, which are used to derive a pulse-shaping matrix used to condition received symbols such that orthogonal symbol streams are recovered.

Provided is a wireless data transmission method for adjusting parameters according to changes of both a signal source and a signal channel. The wireless data transmission method enables wireless data transmission parameters to be dynamically adjusted according to both change of QoS requirements of different transmission media and change of the fading level of a wireless channel by making full use of dual time-variable characteristics of a transmission media service and a wireless transmission channel of a mobile multimedia communication system, enables data rates and the maximum delay requirements of different media services to be achieved by dynamically allocating dedicated service channels, and enables BER performance requirements of different media services to be met by dynamically changing the code rate of a coder and the constellation size of a modulator and adopting channel inversion power control. Meanwhile, the spectrum utilization rate of a wireless communication system is maximized.

The invention relates to a wireless data transmission method capable of regulating parameters simultaneously according to information source and channel variations. The double time-varying characteristic of a transmission media service and a wireless transmission channel of a mobile multimedia communication system is sufficiently utilized; wireless data transmission parameters are dynamically regulated simultaneously according to a variation of QoS (Quality Of Service) requirements of different transmission medias and a variation of a fading level of the wireless channel; by dynamically allocating a special service channel, the data rate and maximum delay requirements of different media services are met; by dynamically changing a code rate of an encoder and a constellation size of a modulator and adopting channel inversion power control, BER (Bit Error Rate) performance requirements of different media services are met; and meanwhile, spectrum utilization efficiency of the wireless communication system is improved to the greatest extent.

The present invention discloses an extraction method for of a threshold voltage of MOSFET on the basis of a drain control generation current. The extraction method provided by the invention comprise: a channel inversion layer is located in the inversion state through adoption of fixation of large gate voltage VG, and at the same time a drain voltage VD is scanned to obtain a curve of a drain control generation current IDC; and when the drain voltage VD is increased up to allow a channel at the edge of the drain end to start the occurrence of exhaustion, the IDC curve is beginning to rapidly increase and turns up a peak, and the point of abrupt change is just a difference of a gate voltage and the drain voltage with respect to a critical point or a turning point inverting up to exhaustion, namely the threshold voltage VT. An accurate, simple and fast test method of MOSFET is provided by the invention. Because the curve presents an abrupt change, the drain voltage point with respect to the turning point inverting up to exhaustion may be easier observed, so that the man-made observation error may be avoided; the operation of obtaining a threshold voltage is simple; and the measurement is fast, and a direct current test is only needed.

The invention relates to communication area especially IP phone. Function of official telephone is implemented on SDH device by using general IP phone. (1) One route of 64 k official telephone is provided in ring network constituted by SDH devices; (2) E1 byte in overhead of regeneration section is as official telephone connection between network cells in ring net, UDP datagram including voice data packet are built; (3) protocol stack transfers EPHONE data through E1 channel, i.e. EPHONE data through protocol stack three layer forwarding can be passed through E1 channel of SDH only; (4) through configuration, based on source IP address, protocol stack identifies EPHONE data; device through OSPF finds route of ring net; (5) in forwarding EPHONE data, channel inversion is carried out from DCC to E1 channel of SDH. The invention is suitable to implementation of official telephone on SDH device based on TCP/IP.

The invention provides a finite block length covert communication implementation method based on channel estimation. In the past, studies on covert communication in a fading channel are supposed thatthe channel is known, or channel estimation is avoided through a channel inversion power control method. However, in practice, channel estimation is inevitably performed in a fading channel due to theideality of channel reciprocity hypothesis. In conventional channel estimation, the optimal pilot number is equal to the number of transmission antennas, but in covert communication, the conclusion may not be established any more. In order to improve the reliability of covert communication, a minimum mean square error estimation method is used for estimating a channel, and the optimal pilot frequency number, the optimal transmitting power, the optimal data number and the optimal transmitting power are designed under the covert constraint condition to maximize the effective rate. Meanwhile, due to the fact that previous studies are generally concentrated on analysis of infinite block lengths, but symbols of the limited block lengths are usually sent in practice, hidden communication underthe limited block lengths is studied through the method.

The invention discloses a relay selection method based on adaptive power transmission, wherein the adaptive power transmission is applied to a relay selection method, thereby facilitating improvement of the system capacity; two policies, including optimal power and velocity self-adaptation and power self-adaptation under channel inversion, are respectively considered, thereby providing beneficial thoughts for the design of the relay selection method; based on self adaptation, the fairness of relay selection is considered, equivalent signal noise ratio is defined, and the self-adaptation is applied to relay selection, thereby facilitating the balancing of network node loads; and when a mobile user is utilized as a relay node, the user satisfaction can be improved.

Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme.

The invention discloses a preparation method of an improved SiC planar MOSFET device. The improved SiC planar MOSFET device is characterized in that a low-doped epitaxial layer of tens of nanometers is grown on the epitaxial surface of a conventional MOSFET, and the doping concentration is on the order of 1e14cm<3>; the improved MOSFET device structure can greatly improve the width of a channel inversion layer, and can weaken the influence of the high interface state of an SiO2/SiC surface and the doped impurity on the channel mobility, thereby improving the conduction characteristics of the device. The preparation method of the improved SiC planar MOSFET device is conductive to further reduce the device specific on-resistance, and can make a better compromise between device conduction characteristics and blocking characteristics.

The invention belongs to the technical field of wireless communication and mobile computing, and discloses a precoder, a construction method, computer equipment, a medium and a terminal.The method comprises the steps that a system model is constructed; precoder design with unequal path loss is carried out; and a precoder for secret communication constructed. The precoder provided by the invention can be regarded as an improved regularized channel inversion (RCI) and has more regularized parameters, and the parameters are obtained by path loss information of a user. The regularization parameter of the precoder is analyzed, numerical search is not needed, and the problem of RCI precoding under the condition of unequal path loss is solved. According to the precoder, the sum rate of the users is improved, the RCI precoder is expanded, and the sum rate of the users is improved under the condition that the path loss of each user is inconsistent. The encoder can also be used for secret communication. The precoder has an analytical solution, so that the complexity of solving the regularization parameter is low.

The invention provides a superconductive field effect transistor as well as a manufacturing method and an application method thereof. A superconductor source electrode, a superconductor drain electrode, a channel region and a grid electrode structure are formed on a semiconductor substrate on an insulator, wherein the channel region is located between the superconductor source electrode and the superconductor drain electrode; and the channel region, the superconductor source electrode and the superconductor drain electrode are the same in doping conducting types. A positive voltage or a negative voltage can be applied to the grid electrode structure through control so as to control on or off of the superconductive field effect transistor. With the adoption of the superconductive field effect transistor, working of nanoscale short channel devices can be realized, the problem of failure of nanoscale short channel inversion devices caused by increasing leakage current of the devices because source drain impurity ions diffuse to a channel is avoided at the same time, and the reliability of the devices is improved. Superconductivity of a semiconductor channel can be realized by using shorter channels, thus the response speed of the devices is greatly quickened.. The superconductive field effect transistor has the characteristics of large current, strong driving force, high speed, rapid response and simplicity in preparing process and is suitable for industrial production.