37 results about "Channel knowledge" patented technology

A method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors may be employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.

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 nd 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 nd 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 method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors may be employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.

A method of one AP accessing a channel occupied by a neighboring AP within CCA range, by acquiring channel knowledge via performing cooperative sounding and setting a null towards the neighboring AP, under certain conditions verifications, is provided herein. The method may include: transmitting and receive signals via a plurality of radio circuitries connected to plurality of antennas; monitoring signals received by the radio circuitries and generating a list of neighboring co-channel access points that each has plurality of antennas and are further located within a clear channel assessment (CCA) range of the access point; and instructing the radio circuitries to transmit a sounding sequence to the list of neighboring access points, and receive Channel State Information (CSI).

Multiple antennas employed at the transmitter (110) and receiver (120) can significantly increase a MIMO system (100) capacity, especially when channel knowledge is available at the transmitter (110). Channel state information may be provided to the transmitter (110) by the receiver (120) in a codebook based precoding feedback. In a proposed approach is proposed in which the receiver (120) conducts a search of precoder elements of a codebook to provide the transmitter (110) with rank information and precoder control index that enhances capacity. Unlike the conventional exhaustive search, the proposed approach reduces complexity by reducing the search space of precoder elements for consideration. Performance loss is minimized by reducing the search space of higher rank precoder elements. For some ranks, the complexity is reduced without any performance sacrifice by grouping the precoder elements of the rank into groups of equivalent capacities and including at most one precoder element from each group into the search space.

An apparatus for use in transmit beamforming to a beamformee having NR receive antennas. The apparatus includes a controller configured to i) construct a partial channel matrix that describes a multiple input, multiple output (MIMO) channel between a beamformer and M receive antennas, wherein M is less than NR, and ii) generate L independent vectors using the partial channel matrix, wherein L is a rank of the partial channel matrix. When a number NS of one or more streams is greater than L, the controller is further configured to i) select the L independent vectors as steering vectors to steer L streams of the plurality of streams, and ii) select NS−L orthogonal vectors in a null space of the L independent vectors as steering vectors to steer a remainder of the streams in the plurality of streams.

A method and apparatus for an access point (AP) accessing a channel occupied by a neighboring AP within clear channel assessment (CCA) range. The method is implemented by setting a transmit null towards the neighboring AP, while acquiring accurate channel knowledge with minimal bandwidth penalty to surrounding networks, via a combination of sparse explicit sounding, and a following implicit channel estimation of the neighboring APs for updating the explicit data achieved by the sparse explicit sounding. An AP implementing the method is also disclosed.

A system and method for transmitter and receiver operation for multiple-input, multiple-output (MIMO) communications based on prior channel knowledge are provided. A method for receiver operations includes receiving a data block, determining if there is confidence in information related to a channel, detecting data in the data block with a first detector in response to determining that there is confidence in the information, and detecting the data in the data block with a second detector in response to determining that there is no confidence in the information. The data block is received over the channel.

A system for acquiring channel knowledge and a method thereof are provided. At least one transmitter generates multiple directional beams in different directions, next modulates the directional beams in the different directions with at least one spreading sequence, so as to enlarge the beam range of each directional beam in the different directions and use the modulated directional beams as training-specific beams in the different directions, and sweeps the multiple training-specific beams in the different directions by using a plurality of antennas, so that at least one receiver measures at least one training-specific beam, and determines the channel knowledge according to the measurement result and beam-related information associated with the at least one training-specific beam, so as to achieve a technical effect of reducing training overhead.

A method in a transmitter for selecting steering vectors for simultaneously transmitting a plurality of streams (NS) between the transmitter and a receiver, where the receiver has NR receive antennas, where the transmitter knows respective channels associated with M receive antennas of the receiver, and where M is less than NR, includes constructing a partial channel matrix that describes a multiple input, multiple output (MIMO) channel between the transmitter and the M receive antennas, generating L independent vectors using the partial channel matrix, wherein L is a rank of the partial channel matrix, selecting a respective steering vector for each of the plurality of streams to be transmitted to the receiver, including, if NS is less than or equal to L, selecting NS of the L independent vectors as the steering vectors, and, if NS is greater than L, (i) selecting the L independent vectors as steering vectors to steer L of the plurality of streams; and (ii) selecting NS−L orthogonal vectors in a null space of the L independent vectors.

Method for allocating a minimum downlink power from a transmitter (1) having nt transmit antennas of a cellular multi-user multi-antenna communications system with N users attached to said transmitter (1). Each user comprises at least one antenna. The method comprising the steps of: generating at said transmitter (1) M random beams (b1 . . . bM); sending said M random beams through all the transmit antennas; calculating at each user a signal-to-noise-interference-ratio for each random beam sent by said transmitter (1); sending back to said transmitter (1) said calculated values of signal-to-noise-interference-ratio, said signal-to-noise-interference-ratio representing a partial channel state information; selecting at said transmitter (1) the M best users which correspond to the M best values of signal-to-noise-interference-ratio per beam.

The embodiment of the invention provides a recognition method and a recognition device for a non-standard channel name. The method comprises the steps of if a speech control text input by a user does not include a standard channel name and matched with a preset channel name template, acquiring a target attribute keyword included in the speech control text according to the preset channel name template, wherein the target attribute keyword and the keyword in the preset channel name templates are the same in attribute; and querying a preset channel knowledge graph according to the target attribute keyword to determine the channel name included by the speech control text, thus allowing a smart television to be switched to a channel indicated by the channel name from the current playing channel. According to the recognition method and the recognition device for the non-standard channel name provided by the embodiment of the invention, a recognition rate of the non-standard channel name during a speech interaction process can be improved, and user experience can be enhanced.

The disclosure relates to a receiver (400), including: a decoder (305) comprising an adjustable receive filter (31 9) for decoding a receive signal (Y) received over a communication channel; and a first channel state information (CSI) handler (401) configured to provide the decoder (305) with receive-side channel state information (H̃) indicating a receive-side estimate of a channel state (H) of the communication channel and to provide the decoder (305) with transmit-side channel state information (Ĥ) indicating a transmit-side estimate of the channel state (Η) of the communication channel, wherein the decoder (305) is configured to adjust the receive filter (319) based on the transmit-side channel state information (Ĥ) if the transmit-side channel state information (Ĥ) is a less good estimate of the channel state (Η) of the communication channel than the receive-side channel state information (H̃). The disclosure further relates to a precoding system (500) including such receiver (400).

The invention discloses a self-adaptive communication method and system for links among micro-nano satellite groups, belongs to the technical field of communication among micro-nano satellite groups, and aims to solve the problem of low communication efficiency or data loss caused by the fact that the communication rate cannot be dynamically adjusted in the conventional inter-satellite link communication method. The method is technically characterized by comprising the following steps of: establishing an inter-satellite link communication channel knowledge base according to an inter-satellite link communication error rate threshold value requirement of a micro-nano satellite group; according to the real-time communication distance between the two micro-nano satellites, selecting the maximum communication rate value as the optimal communication rate value, and selecting the corresponding coding modulation scheme as the optimal coding modulation scheme; and carrying out coding and modulation processing on inter-satellite communication data according to the optimal coding modulation scheme, and carrying out inter-satellite link communication according to the optimal communication rate value. According to the method, high-efficiency and reliable transmission of telemetry data is realized, and the method is of great significance in improving self-adaptive signal processing of inter-satellite links of a micro-nano satellite group system.