1281 results about "Orthogonal frequency code division multiplexing" patented technology

The invention provides a VDSL ultra-low time delay communication method and system, and relates to the technical field of communication, and the method comprises the steps: encrypting a clock synchronization channel through a quantum key distribution protocol, dynamically dividing micro time slot resources in an orthogonal frequency division multiplexing symbol period, and generating a dynamically adjusted micro time slot resource distribution result; calculating an optimal phase offset matrix of the metasurface intelligent reflecting surface through a depth deterministic strategy gradient algorithm to obtain an optimized electromagnetic wave propagation path; generating a global optimization check matrix by aggregating the locally trained lightweight error correction model gradient of each node to obtain a compensated data stream; and constructing a causal graph model dynamic pruning high-entropy path to minimize causal entropy, through multi-agent reinforcement learning, taking time delay-energy efficiency as a game target to decide an optimal modulation order and a subcarrier switching strategy, and obtaining an optimized stable communication link. According to the invention, high-reliability and low-delay communication basic support is provided for high-precision intelligent manufacturing.

The invention discloses a wide-narrow integrated ad hoc network method, and belongs to the technical field of network communication. The method comprises the following steps: a network node generates dynamic topology information based on a narrow-band communication module periodic broadcast state beacon; according to the link quality and the node load in the topological information, coordinating the resource allocation of broadband and narrowband channels by adopting a load-aware time slot allocation algorithm; data are classified according to service types, broadband data are modulated and transmitted by adopting orthogonal frequency division multiplexing, and narrowband control instructions are modulated and transmitted by adopting differential phase shift keying; when the link quality is deteriorated, the link is switched, and the transmitting power and the frequency band parameters are dynamically adjusted; and adaptive switching and data distribution of wide and narrow band communication modes are realized. According to the method, the problems of difficulty in topology maintenance and low bandwidth and narrowband resource allocation efficiency in a high-dynamic network scene are solved, the network adaptability, the anti-interference capability and the resource utilization rate are remarkably improved through a dynamic cooperative bandwidth and narrowband communication mode, and meanwhile, the protocol switching overhead and energy consumption are reduced.

The invention provides a life detection method and system based on radar signal processing, and relates to the technical field of radar signal processing, and the method comprises the steps: collecting a radar echo signal of a target region, controlling a phased array radar transmitting antenna array to transmit an orthogonal frequency division multiplexing dual-frequency continuous wave radar signal, and transmitting the dual-frequency continuous wave radar signal. Inputting the processed radar echo signal into an orthogonal demodulation module for synchronous coherent demodulation to obtain a baseband signal; inputting the feature vector into a multi-task deep learning network integrated with an attention mechanism for feature fusion and target recognition to obtain a second processing signal; obtaining a target characteristic frequency spectrum by calculating the time-frequency distribution of the second processing signal, and judging whether a life body exists in the target area or not according to the time-varying characteristics of the respiratory frequency component and the heartbeat frequency component and the amplitude fluctuation rule; and calculating three-dimensional space coordinates of the life body through a multi-base-station cooperative positioning algorithm, and outputting a detection result containing the three-dimensional space coordinates and the life body feature information.

The invention provides an HPLC (High Performance Liquid Chromatography) and micropower wireless dual-mode communication method, which belongs to the technical field of multiplexing communication, is used for realizing cooperative transmission of power line carrier communication and micropower wireless communication, and comprises a modulation end method and a demodulation end method. According to the modulation end, firstly, HPLC and micropower wireless signals are collected, and band-pass filtering and spectrum sensing are carried out, so that frequency bands which do not interfere with each other are obtained. Then, a unified time reference is established, transmission delay is calculated, and delay compensation is carried out; and then, modulating and transmitting by adopting an orthogonal frequency division multiplexing technology. And at a receiving end, main and standby channels are selected according to the signal strength, and demodulation and data recovery are performed by adopting an adaptive modulation and demodulation technology. According to the scheme, the advantages of HPLC and micropower wireless are fully utilized, fusion of two communication technologies is achieved, and the technical problem that effective cooperation is difficult to achieve due to the fact that existing HPLC and micropower wireless communication often adopt independent communication carriers and transmission protocols is solved.

The invention provides a clock error compensation method and an orthogonal frequency division multiplexing system using the clock error compensation method, and the compensation method comprises the steps: determining a second synchronous pilot symbol at a corresponding position in a received signal through a first synchronous pilot symbol of an orthogonal frequency division multiplexing symbol selected according to a system pilot signal; the method comprises the following steps: receiving a received signal, further determining a first synchronous pilot signal and a second synchronous pilot signal, after synchronizing the first synchronous pilot signal and the second synchronous pilot signal, determining the position of each orthogonal frequency division multiplexing symbol in the received signal relative to the second synchronous pilot symbol, and demodulating the received signal based on the position. According to the method, the phase deviation value of each orthogonal frequency division multiplexing symbol in the received signal relative to the second synchronous pilot symbol in the frequency domain is determined, and finally, frequency domain phase compensation is performed on each orthogonal frequency division multiplexing symbol in the received signal according to the calculated phase deviation value, so that clock error compensation of the received signal is realized, and the precision of phase compensation is improved.

Disclosed are systems, methods, and structures employing a distributed fiber optic sensing (DFOS) / distributed acoustic sensing (DAS) system operating as an underwater wireless acoustic antenna in which an optical fiber sensor cable serves as a distributed acoustic antenna that receives multiple data from transmitters using an optical interrogator. Sensing channels, in the form of acoustic-antenna-array systems are located near transmitters taking advantage of the fact that these channels are automatically synchronized. The sensing channels may also be manually selected from software controlling the interrogator, and acoustic repeaters may be introduced as one data transmission mechanism. Acoustic tata transmission using an orthogonal frequency division multiplexed (OFDM) signal is demonstrated as a cure for data transmission using a DAS, such as multipath fading impacting bit error rate (BER) and limitations in acoustic transmission bandwidth.

The invention provides an optical-electric hybrid ultra-low time delay communication method and system, and relates to the technical field of communication, and the method comprises the steps: outputting a global synchronous clock signal with clock jitter less than 1ppm, dynamically dividing micro time slot resources in an orthogonal frequency division multiplexing symbol period, and generating a dynamically adjusted micro time slot resource distribution result; calculating an optimal phase offset matrix of the metasurface intelligent reflecting surface through a depth deterministic strategy gradient algorithm to obtain an optimized electromagnetic wave propagation path; generating a global optimization check matrix by aggregating the locally trained lightweight error correction model gradient of each node to obtain a compensated data stream; and constructing a causal graph model dynamic pruning high-entropy path to minimize causal entropy, through multi-agent reinforcement learning, taking time delay-energy efficiency as a game target to decide an optimal modulation order and a subcarrier switching strategy, and obtaining an optimized stable communication link. According to the invention, high-reliability and low-delay communication basic support is provided for high-precision intelligent manufacturing.

Methods and systems are disclosed for resource management on Sidelink for vehicle to everything (V2X) scenarios. Example methods and systems for a Resource Structure on Sidelink are disclosed. Control and data channels may be Frequency Division Multiplexed (FDMed) or Time Division Multiplexed (TDMed) with an Orthogonal Frequency Division Multiplexing (OFDM) waveform. Example methods and systems for a Resource Configuration on Sidelink are disclosed. The resource configuration may be statically configured or may be locally configured. Example methods and systems for Assisted Resource Allocation are disclosed. Assisted Sensing may be performed by a group lead or RSU and local scheduling may be performed by a group lead or RSU.

Systems, methods, and instrumentalities are described herein for adaptive waveform selection for wireless communication. In examples, the wireless transmit / receive unit (WTRU) may be configured with the orthogonal frequency-division multiplexing (OFDM) initially. If the WTRU, which may support dynamic waveform switch, receives system information blocks (SIBs) from multiple cells where at least one of them supports dynamic waveform switch, the WTRU may prioritize the initial access with the cell(s) that support dynamic waveform switch. If the WTRU supports dynamic waveform switch, the WTRU may send a physical uplink shared channel (RUSCH) in msg3 at a configured grant, which may be offset by a preconfigured number of slots with a waveform that is different from the preconfigured waveform type.

Methods and apparatus in a fifth-generation wireless communications, including an example method, in a wireless device, that includes receiving a downlink signal comprising an uplink access configuration index, using the uplink access configuration index to identify an uplink access configuration from among a predetermined plurality of uplink access configurations, and transmitting to the wireless communications network according to the identified uplink access configuration. The example method further includes, in the same wireless device, receiving, in a first subframe, a first Orthogonal Frequency-Division Multiplexing (OFDM) transmission formatted according to a first numerology and receiving, in a second subframe, a second OFDM transmission formatted according to a second numerology, the second numerology differing from the first numerology. Variants of this method, corresponding apparatuses, and corresponding network-side methods and apparatuses are also disclosed.

The embodiment of the invention provides a synchronization signal transmission method, device and system, which are used for realizing synchronization signals compatible with different types of terminal devices. The method comprises: determining a synchronization signal comprising a plurality of subsequences, each of the plurality of subsequences being mapped to a subcarrier of orthogonal frequency division multiplexing (OFDM), the bandwidth of the synchronization signal being greater than or equal to the bandwidth of any one of the plurality of subsequences; and sending a synchronization signal to the terminal device, wherein the synchronization signal is used for the terminal device to execute downlink synchronization.

A reference signal receiving method includes: obtaining, at a user equipment, a sidelink resource pool configuration including configuration parameters of one or more SL OFDM resources (sidelink orthogonal frequency division multiplexing resources) including one or more SL OFDM RS resources (SL OFDM reference signal resources) each dedicated to carrying one or more sidelink reference signals; receiving, at the user equipment, reference signal control information indicating a first resource location of at least one of the one or more SL OFDM RS resources; decoding, at the user equipment, the reference signal control information; and using, at the user equipment, the at least one of the one or more SL OFDM RS resources to receive a first reference signal.

Apparatuses and methods for channel state information (CSI) processing for CSI reporting. A method performed by a UE includes receiving a configuration about a CSI report. The configuration includes information about a parameter codebookType set to ‘typeI-MultiPanel-r19’ or ‘typeII-Doppler-r19’. The method further includes based on the configuration, processing the CSI report and determining the CSI report. Processing of the CSI report occupies OCPU CSI processing units (CPUs) for a number of orthogonal frequency division multiplexing (OFDM) symbols. The method further includes transmitting the CSI report.

The invention discloses a sparse Bayesian parameter estimation method based on a Markov chain Monte Carlo (MCMC). The sparse Bayesian parameter estimation method is suitable for super-resolution target number detection and high-precision target parameter estimation in a communication perception integration (ISAC) scene. The method comprises the following steps: a base station transmits an orthogonal frequency division multiplexing (OFDM) signal and receives a target reflection echo; performing frequency domain transformation on the echo signal and constructing a high-dimensional observation vector; target parameters are modeled as random variables including path complex gain, time delay, Doppler frequency shift and angle, and a learnable parameterized sensing matrix is constructed; the sparse Bayesian framework is combined with MCMC sampling, the parameters are iteratively updated through random small-batch gradient optimization and the Metropolis-Hastings criterion, and finally the estimation result of the target parameters is output. According to the method, the precision limitation of a traditional gridding method is broken through, super-resolution parameter estimation is achieved, meanwhile, the calculation complexity and the storage overhead are remarkably reduced, and the method is suitable for the high-precision sensing requirement in a 6G communication system.

The invention relates to the technical field of backscatter communication, and discloses a single-receiver WiFi backscatter method based on frequency domain cyclic shift. The method comprises the following steps: a transmitting end modulates data onto N frequency domain subcarriers, converts the N frequency domain subcarriers into N time domain samples through inverse fast Fourier transform, and forms an orthogonal frequency division multiplexing WiFi signal taking an OFDM symbol as a basic unit after adding a cyclic prefix; the label receives the WiFi signal, and performs sub-symbol-level modulation on an OFDM symbol in the WiFi signal based on a modulation technology of frequency domain cyclic shift; and the receiver determines the cyclic shift value of the frequency domain subcarrier through the frequency domain invariance of the OFDM symbol, and demodulates the received reflected signal to recover the label data. According to the invention, sub-symbol-level label data modulation is realized, the data transmission efficiency is improved, only a single symbol bandwidth is needed, and the waste of spectrum resources is avoided.

The invention provides a positioning method and system for a double-layer optical fiber heterogeneous communication hybrid topology networking, and relates to the technical field of communication, and the scheme is as follows: constructing a double-layer optical fiber multi-node communication architecture to carry out heterogeneous network convergence to obtain a double-layer optical fiber heterogeneous communication positioning network, and optimizing a network channel; constructing a micro-nano device and constructing a multi-signal cooperative communication positioning model based on an ultra wide band and an orthogonal frequency division multiplexing communication technology; optimizing a network architecture of a multi-signal cooperative communication positioning model based on a star-ring topological structure; performing dynamic polling on the double-layer optical fiber heterogeneous communication positioning network based on the optimized model to obtain node real-time information; and estimating and positioning the node real-time information by combining a circumference positioning method and a time difference of arrival positioning method, and obtaining and outputting a double-layer optical fiber heterogeneous communication networking positioning report. The invention aims to improve the common multi-path effect and signal attenuation problems in the underground roadway environment and realize high-precision positioning of the target position.

The invention discloses a signal transmission method and device based on orthogonal matrix precoding. The method comprises the steps that four chaotic sequences X, Y, Z and W are generated through a four-dimensional chaotic model according to a key initial value; performing bit interleaving on the original data by using X and W to obtain first data; performing serial-to-parallel conversion and QPSK mapping to obtain a mapping signal; scrambling the subcarriers and symbols of the mapping signals by using Y and Z to obtain encrypted data; carrying out IFFT (Inverse Fast Fourier Transform) on the encrypted data, adding a cyclic prefix, and carrying out parallel-serial conversion to obtain an encrypted data stream; performing binary conversion and serial-parallel conversion on the key initial value to obtain a square matrix K, and shaping the square matrix K by using a public key to obtain a key matrix; performing serial-to-parallel conversion, QPSK mapping, IFFT, cyclic prefix addition and parallel-to-serial conversion on the key matrix to obtain a key stream; and performing linear superposition on the encrypted data stream and the key stream through power distribution to obtain a power division multiplexing orthogonal frequency division multiplexing signal, and transmitting the power division multiplexing orthogonal frequency division multiplexing signal.

Provided are a method and a device for transmitting and receiving a new radio technology (NR) physical downlink control channel (PDCCH) in a wireless communication system. In one or a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a slot, a terminal monitors a PDCCH transmitted by a base station, wherein the slot is used for a long term evolution (LTE) cell-specific reference signal (CRS), and the terminal receives, from the base station, in at least one OFDM symbol in the slot, a demodulation reference signal (DM-RS) for the decoding of the PDCCH. A resource element (RE) used for the DM-RS for the decoding of the PDCCH does not overlap with an RE used for a LTE CRS.

The invention relates to the technical field of wireless semantic communication, and discloses a semantic information transmission method, device and equipment and a storage medium, a sending end extracts features of to-be-transmitted data, and matches the features with vectors in a preset discrete vector codebook to obtain discrete feature vectors; and determining an orthogonal frequency division multiplexing time-frequency resource distribution grid according to the feature importance weights of the discrete feature vector and the initial feature vector, generating a sending signal, and transmitting the sending signal to a receiving end. And the receiving end inputs the semantic feature vector obtained after processing the received signal into the vector quantization variational self-decoder, and the semantic feature vector is matched with the vector in the discrete vector codebook again to correct the transmission error, thereby obtaining the reconstructed data to be transmitted. Discretization processing of the features is achieved through a discrete vector codebook, important semantic feature bits are quantized according to the importance weight of each feature and then distributed to orthogonal frequency division multiplexing for transmission, so that key semantic information is protected, and anti-interference transmission of the semantic information is achieved.

Methods, systems, and devices for wireless communications are described. A transmitter may modulate a set of bits into an on-off keying (OOK) sample sequence for wireless transmission to a receiver in a set of frequency resources. The transmitter may apply a transform (e.g., a discrete Fourier transform (DFT)) to the OOK sample sequence to generate a frequency domain representation of the OOK sample sequence. In some cases. the transmitter may, using an orthogonal frequency division multiplexing (OFDM) waveform generator, generate an OFDM waveform based on mapping the frequency domain representation of the OOK sample sequence to a set of resource elements of the set of frequency resources. In some cases. the transmitter may transmit the OFDM waveform to the receiver via the set of frequency resources.

The invention relates to the field of underwater acoustic communication and detection, in particular to a waveform optimization method and system for an underwater acoustic detection and communication integrated system. According to the method, a constant modulus phase is taken as a constraint, a reserved subcarrier phase is taken as an optimization variable, and a multi-objective function for joint optimization of a peak-to-average power ratio and a non-periodic autocorrelation integral sidelobe ratio is constructed; a population is initialized, an objective function is evaluated, and a parent population is obtained through non-dominated sorting and crowding distance calculation; generating filial generations through selection, crossover and variation, combining the filial generations with the parent generations, and updating sorting and crowding distance to maintain population diversity; introducing a local gradient descent refinement mechanism, carrying out gradient iteration adjustment on an optimized individual under a constant modulus phase condition, and adaptively adjusting a crossover probability, a mutation probability and a phase variation scale according to a diversity evaluation result; and outputting a Pareto optimal solution set after the maximum number of iterations is reached, and obtaining an optimized sounding and communication integrated orthogonal frequency division multiplexing signal, so that the underwater communication and detection comprehensive performance can be effectively improved.

Conventional Orthogonal frequency division multiplexing (OFDM) is unable to retain its orthogonality and suffers loss in performance in high Doppler circumstances. The present disclosure converts a signal received in delay-time domain into delay-Doppler domain and extracts a guard band region from the received converted signal. A 2-dimensional fast Fourier transform is performed on guard band region extracted from received converted signal. A 2-dimensional fast Fourier transform of the received converted signal is divided with the 2-dimensional fast Fourier transform of transmitted signal to extract phase information. A dictionary is created using a pre-defined set of values of delay and Doppler. A sparse recovery problem is formed for received converted signal using an orthogonal matching pursuit algorithm. One or more parameters are estimated by identifying one or more locations pertaining to the one or more columns corresponding to L significant non-zero locations comprised in sparse vector of sparse recovery problem.

The disclosure deals with system and method for discerning the radius maximizing reliability for binary modulation on conjugate-reciprocal zeros (BMOCZ) implemented with both a maximum likelihood (ML) and direct zero-testing (DiZeT) decoder. The optimal radius for BMOCZ is disclosed to be a function of the employed decoder. The radius maximizing the minimum distance between polynomial zeros does not maximize the minimum distance of the final code. While maximizing zero separation offers an almost optimal solution for the DiZeT decoder, the ML decoder outperforms the DiZeT decoder in both additive white Gaussian noise (AWGN) and fading channels when the radius is chosen to maximize codeword separation. Different sequence-to-subcarrier mappings for BMOCZ-based orthogonal frequency division multiplexing (OFDM) are analyzed to highlight a flexible time-frequency mapping approach that avoids distortion introduced by a frequency-selective channel at the expense of higher peak-to-average power ratio (PAPR).

The invention discloses a symbol processing method, a communication device and a communication system, and relates to the technical field of communication. The method comprises: a first communication device generating a first time slot, the first time slot comprising a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols, the plurality of OFDM symbols comprising a first OFDM symbol and a second OFDM symbol, the first OFDM symbol being the first OFDM symbol in the plurality of OFDM symbols, the first OFDM symbol comprising a first cyclic prefix (CP), the second OFDM symbol comprising a second CP, the length of the first CP being greater than the length of the second CP, the length of the first CP being greater than the length of the second CP, and the length of the second CP being greater than the length of the second CP; the length of the first CP is greater than a first value, and the first value corresponds to a subcarrier interval; a first communication device sends a first time slot, and correspondingly, a second communication device receives the first time slot. By adopting the embodiment of the invention, the signal loss can be reduced, and the demodulation performance is ensured.

Embodiments of the present disclosure are related, in general to communication, but exclusively related to methods and systems methods for transmitting a waveform. The waveform is a pre-DFT RS and data multiplexed DFT-S-OFDM with excess bandwidth shaping and MIMO. Also, embodiments of the present disclosure relate to methods of detecting the received data. The method for transmitting a waveform, comprising generating, by one or more transmitters, at least one data sequence and at least one reference sequence (RS). Also, the method comprises time-multiplexing the at least one data sequence with the at least one RS, to generate a multiplexed sequence. Further, the method comprises generating a filtered-extended bandwidth DFT-s-OFDM symbol using the multiplexed sequence. The filtered-extended bandwidth DFT-s-OFDM symbol generated by the one or more transmitters is transmitted in an OFDM symbol.

The invention discloses a random access preamble and detection algorithm design based on low earth orbit satellite communication. Specifically, firstly, a novel lead code with a plurality of subsequences is provided, in order to enlarge the number of available lead codes in a wave beam, a ZCM sequence is introduced to form the subsequences, and orthogonal frequency division multiplexing is adopted for modulation and is sent to a channel. Subsequently, a timing advance (TA) detection algorithm is proposed. The first sub-sequence is used for decimal time delay detection, and the other sub-sequences are used for integer time delay detection. In addition, the peak detection ingeniously utilizes the variance of the power delay spectrum, so that the detection performance is improved. Finally, a simulation result shows that the lead code provided by the invention is almost not influenced by frequency offset, does not need pre-compensation, and is suitable for being applied to low-orbit satellite communication with relatively large frequency offset.

In some implementations, a non-terrestrial network (NTN) platform may transmit a radio frequency (RF) signal toward the earth, the RF signal including an orthogonal frequency division multiplexing (OFDM) waveform having a plurality of symbols, the plurality of symbols including a JCS symbol and one or more non-JCS symbols, where: the RF signal is incident on an area of the earth defining a coverage area, and the one or more non-JCS symbols are not incident on the area of the earth defining the coverage area; and the duration of the cyclic prefix (CP) of the JCS symbol is a function of the width of the coverage area. The NTN platform may receive one or more reflections of a JCS symbol at the NTN platform.

The invention relates to the technical field of communication, and discloses an anti-interference communication sensing integrated beam forming method and system. The method comprises the following steps: generating an integrated waveform based on an orthogonal signaling base and a random data symbol; the sensing ranging performance is evaluated through periodic and non-periodic autocorrelation functions, time-frequency resource allocation of the waveform is optimized based on the performance, and an optimized waveform is generated; obtaining channel state information, carrying out interference source identification, and calculating a beam forming weight according to an identification result; mapping the optimized waveform to a time-frequency resource lattice of a frame according to orthogonal frequency division multiplexing to generate a frame structure signal; inputting the frame structure signal into a multi-antenna array, and regulating and controlling the phase and amplitude of each antenna unit through a beam forming weight to form a directional beam with a main lobe aligned with a target and a null aligned with interference; the target and interference changes are monitored in real time, the beam forming weight and waveform time-frequency resource allocation are dynamically updated, the anti-interference capability is improved, and the communication perception integration performance is enhanced.

Provided are a communication method and a communication device, the method comprising: determining a transmission waveform of a signal, the transmission waveform being related to a threshold of a first parameter, the first parameter comprising: a modulation order and a roll-off factor, the transmission waveform is an orthogonal frequency division multiplexing QAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of orthogonal amplitude modulation or an orthogonal frequency division multiplexing OQAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of offset orthogonal amplitude modulation, and the roll-off factor is determined based on the transmission bandwidth and the number of symbols carried by the transmission waveform. And transmitting or acquiring the signal. In the method provided by the invention, the network equipment or the terminal equipment can determine the transmission waveform of the signal according to the set threshold value of the modulation order and the threshold value of the roll-off factor, so that the output power supporting higher power amplifiers can be obtained, and a larger signal coverage range can be obtained.

A sensing method, which can be applied to a communication and sensing integrated system based on orthogonal frequency division multiplexing (OFDM). The method comprises: acquiring at least two parameter configurations, wherein the at least two parameter configurations comprise a first parameter configuration for sensing and a second parameter configuration for sensing, the first parameter configuration comprises a first subcarrier spacing (SCS), and the second parameter configuration comprises a second SCS, the first SCS being greater than the second SCS; and performing sensing on the basis of the at least two parameter configurations. Since the distance of sensing and sounding is restricted by the length of an OFDM symbol, and the length of the OFDM symbol is usually the reciprocal of an SCS, a relatively large first SCS corresponds to a relatively short symbol length, and can thus be used to sense and sound the shortest minimum distance possible, and a relatively small second SCS corresponds to a relatively long symbol length and can acquire higher symbol energy at a receiving side, and can thus be used to sense and sound a greater distance, thereby enlarging the range of sensing and sounding.