482 results about "Pseudorandom sequence" patented technology

A method of operating a wireless mesh network comprises generating a pseudorandom sequence element in a transmitting device and a receiving device of the network using information shared by the transmitting and receiving devices. The pseudorandom sequence element is then used to calculate a communication channel/timeslot assignment for communication between the transmitting wireless device and the receiving wireless device.

A method of performing ranging and detection with an array lidar system and the array lidar system include a first illuminator to transmit a first pseudorandom binary sequence of pulses, the first pseudorandom sequence of pulses resulting in first reflections, and a second illuminator to transmit a second pseudorandom sequence of pulses, the second pseudorandom sequence of pulses being transmitted at least partly concurrently with transmission of the first pseudorandom sequence of pulses, the second pseudorandom sequence of pulses resulting in second reflections. A receiver receives the first reflections and the second reflections and associates the first reflections with the first illuminator based on a result of correlating the first reflections with the first pseudorandom sequence of pulses and a result of correlating the first reflections with the second pseudorandom sequence of pulses, the receiver includes an optical detector array and a processor.

The invention discloses a pseudorandom bar code applied to a digital level bar code ruler, belonging to the technical field of manufacture of instruments of surveying and mapping. The pseudorandom bar code is formed by alternatively arranging a plurality of light and shade stripes with different widths, wherein the widths and light and shade changes of the strips are modulated by a plurality of pseudorandom sequences. The strips in the bar code comprise coarse code strips for remote measurement and thin code strips for close measurement. The thin code strips are formed by alternatively arranging light and shade strips with smaller widths, and the width changes of the light strips and shade strips are respectively modulated by a pseudorandom sequence. The coarse code strips are formed by arranging light and shade strips with bigger widths, and the widths and light and shade changes of the strips are modulated by a pseudorandom sequence. The coarse code strips are regularly embedded in the fine code strips to form a complete bar code. The pseudorandom bar code is characterized in that a plurality of pseudorandom sequences are alternatively coded for modulating the widths and light and shade changes of the strips. The pseudorandom bar code has the advantages of compatibility with remote measurement and close measurement, capability of forward measurement and backward measurement, simplicity in making a staff gauge, low requirement for a hardware system, small decoding operand, and rapidness and accuracy in identification.

A method and system of the present invention includes the creation and transmission of a MAC header that includes a first MAC header portion and at least two scrambler recovery fields arranged on the two sides (before and after) of a header FEC portion. The invention includes determining whether a scrambler initialization field received at the physical layer was received in error, and if so, evaluating either one of the de-scrambled values of the two scrambler recovery fields in relation to a table to determine a pseudorandom sequence initialization value that corresponds to a given de-scrambled scrambler recovery field value. Once the corresponding pseudorandom sequence initialization value is determined, that value may be used to further de-scramble the data in the data frame to produce a correctly de-scrambled data frame.

A position sensor encodes absolute position via n consecutive members of a pseudorandom sequence of bits, where each bit (30a-30k) comprises a region of high transmission or reflectivity adjacent to a region of low transmission or reflectivity. The pseudorandom sequence is chosen such that every series of n consecutive bits (30a-30k) in the sequence is predominantly formed from a predetermined bit value (1 or 0). The light transmitted or reflected from the series is therefore detected as a substantially periodic intensity pattern (42), which can be processed via Fourier analysis to yield an accurate interpolation of relative position. An example is given of a pseudorandom sequence, which can be represented as a cyclic Manchester code, in which at least 8 members of every series of 11 consecutive bits has a bit value of 1.

Novel methods and structures are disclosed herein which employ pseudorandom sequences to spatially arrange multiple sources in a pseudorandom source array. The pseudorandom source array can replace the single source in analytical instruments relying on spatial separation of the sample or the probe particles/waves emitted by the sources. The large number of sources in this pseudorandom source array enhances the signal on a position sensitive detector. A mathematical deconvolution process retrieves a spectrum with improved signal-to-noise ratio from the detector signal.

The invention relates to an image encryption algorithm based on a chaotic system, used for solving security problems that the image encryption algorithm is small in key space and poor in capacity of resisting to plaintext attacks. The algorithm comprises four modules such as a hyperchaos sequence generator, a forward diffusion module, a scrambling module and a reverse diffusion module. Firstly thehyperchaos Chen system is used for generating four chaotic pseudorandom sequences, a chaotic sequence and a plaintext image are used for performing forward diffusion operation to acquire a matrix A,then computation is performed in combination with the pseudorandom sequences and information related to the plaintext image to acquire a scrambled coordinate, the coordinate scrambling is performed onthe matrix A to acquire a matrix B, and at last the chaotic pseudorandom sequences and the matrix B are used for performing reverse diffusion operation to acquire a ciphertext image C. An experimentsimulation result expresses that the algorithm can improve the defect that the image encryption algorithm is small in key space, effectively resist to statistical attacks, differential attacks, and chosen-plaintext attacks, and achieve good encryption effect.

The invention provides a method of hyperchaos pseudorandom sequence generation. (1) select hyperchaos mapping and set initial values thereof x (0) and y(0); (2) carry out iterative computation by input values x(i) and y(i), and obtain output values x(i+1) and y(i+1); (3) undergo nonlinear transformation of x(i+1) and y(i+1), the transformation method is to take the odd bits of x(i+1) and the even bits of y(i+1) to be combined and then take the reverse sequence thereof as the value of the new sequence z(i+1), and at this time the sequence z(i+1) is a real-value sequence; (4) the real-value sequence z is binarized to be a 0-1 sequence, i.e. the pseudorandom sequence output is obtained. The hyperchaos pseudorandom sequence provided in the invention is characterized by strong safety and security, good random properties, simple and rapid generation, and a plurality of autocorrelation properties close to Delta function and cross correlation properties close to zero, being able to be widely applied to the fields like data encryption, secure communication and information safety and so on.

A system and method for determining a location. The system employs encoded information devices dispersed through the environment, each having, a non-unique code associated therewith. The codes from the encoded information devices are acquired as a reading device passes nearby, and stored. The codes from a proximate set of information devices are correlated with a map or mapping relation to determine one or more consistent positions within the environment. The information devices are preferably passive acoustic wave transponders and the mapping relation may be a pseudorandom sequence or a defined map.

The invention discloses a continue phase-extended binary phase shift keying (CP-EBPSK) communication system for pseudorandom sequence phase modulation and a communication method thereof. On the basis of a CP-EBPSK modulation mode, the CP-EBPSK communication system comprises a CP-EBPSK modulator of pseudorandom sequence phase modulation and a CP-EBPSK demodulator of pseudorandom sequence phase modulation. According to the CP-EBPSK modulator of pseudorandom sequence phase modulation, a pseudorandom sequence generator is added to an original CP-EBPSK modulator and the pseudo random number generated by the pseudorandom sequence generator is utilized to randomly select a symbol of the delta. And the CP-EBPSK demodulator of pseudorandom sequence phase modulation includes an impulse filter that is used for highlighting phase modulation information of a received signal and eliminating the polarity changes, so that the demodulation performance is not influenced by pseudorandom sequence modulation. According to the invention, advantages of narrow bandwidth occupied by the modulation signal, low interference, simple realization, wide code rate adaptive range and flexible application.

The invention discloses a controlled quantum security direct communication method based on four particle cluster states. Alice and Bob respectively serve as a legal information sender and a legal information receiver during a quantum communication process, and Charlie serves as a credible scheme control party; information security is achieved by randomly inserting a single photon to perform measurement-based comparison detection, and communication starts after security detection; Alice uniformly divides the prepared four particle cluster states into two groups, after being subjected to an XOR operation with a pseudorandom sequence, the sent information is encoded on the two particles reserved by Alice via unitary transformation. Alice performs Bell-based measurement on reserved particles, and sends measurement information to Bob, and Bob recovers the original sequence via an initial state sent by Charlie after the measurement information is compared. The four particle cluster states used by the method has good entanglement, connectivity and damage resistance, only the receiver Bob in the method gets the permission of the controller Charlie, Bob can recover the original information, so that the information can be effectively prevented from being attacked during a transmission process, and an implementation process is simple.

The invention discloses a wireless sensor network data traceablility method based on a pseudorandom sequence. The method is characterized in that the method comprises a coding stage and a decoding state of traceablility information, wherein in the coding stage, a source node and a plurality of forwarding nodes enable orthogonal code pieces of themselves to serve as the traceablility information which is written to a preorder sequence of a data packet after being added, the code pieces are allocated autonomously by a base station during construction of the network, and after the data packet arrives at the base station, decoding starts; and in the decoding state, the base station enables the code pieces of all nodes managed thereby to calculate inner product with the preorder sequence of the data packet respectively, a forwarding path node unordered set is obtained according to the inner product result, and finally, the base station restores forwarding paths by sending a plurality of internet control message protocol messages having different time of live (TTL) values and obtaining the traceablility result. The pseudorandom sequence is utilized to realize reuse effect; and through extended operation codes, richer traceablility information is transmitted, thereby suppressing data degeneration, compressing the traceablility information to the largest degree, improving information processing speed in a wireless sensor network, and reducing traceablility cost.

The invention discloses an anti-pollution network encoding method based on probability detection, which comprises the following steps of: each node of the network randomly selects t keys from a key pool by adopting a probability key predistribution mechanism; an information source node cuts and expands information into n original vectors; the information source node selects t pairs of safety parameters and a pseudorandom sequence generator and computes t information authentication codes for each original vector by utilizing the t keys; the information source node or an intermediate node can compute t information authentication codes for new code vectors by utilizing homogeneity; the intermediate node or an information sink node authenticates the integrality and the effectiveness of received code vector data by utilizing shared keys of the intermediate node or the information sink node and the information source node; and the information sink node can decode to obtain original information after receiving n linearly independent code vectors and authenticating the n linearly independent code vectors. The invention has good safety property, high pollution detection probability, little communication overhead and fast authentication and is suitable for the safety application of network codes.

Systems and methodologies are described that facilitate efficiently indicating parameter(s) associated with a base station utilizing synchronization signals in a wireless communication environment. For instance, relative locations of a PSC and a SSC in a radio frame can be a function of a parameter. Further, a PSC sequence utilized to generate PSCs can be selected based upon a parameter. Moreover, inclusion or exclusion of PSCs from a radio frame can be a function of a parameter. Additionally or alternatively, pseudo random sequence mappings (e.g., to cell IDs, tone locations) can be a function of a parameter. Example parameters can be whether the base station is part of a TDD or a FDD system, whether the radio frame employs FS1 or FS2, whether the base station is associated with a macro or a femto cell, or whether the base station is associated with a unicast or a multicast system.

In a touch panel system of the present invention, a touch pen is configured of an electronic pen that signals can be input into and output from. A touch panel controller includes a synchronization signal transmission unit that transmits a synchronization signal to the electronic pen during synchronization signal transmission periods immediately before each of a first signal line drive period and a second signal line drive period. The synchronization signal transmission unit transmits the synchronization signal of which the waveform is configured of a Manchester-coded pseudorandom sequence having periodicity to the electronic pen during the synchronization signal transmission period. The electronic pen includes a synchronization signal detecting unit that detects the synchronization signal.

The invention provides a high-speed moving target position and posture measurement method based on coding structured light, belongs to the technical field of computer vision measurement, and relates to the large-visual-field and small-target high-speed moving target position and posture measurement method. The method includes the steps of projecting a colored grid line containing coding information to a measured area through a colored projector, continuously shooting structured light coding grid line patterns, deformed through moving object surface modulation, through a high-speed camera, achieving corresponding point matching of an imaging plane and a projection plane after digital image decoding to obtain phase position change information, reversely calculating the three-dimensional dynamic morphology of a high-speed moving object through system structure parameters, matching the measured point with a prior model established on the basis of to-be-measured geometrical parameters, and finally accurately measuring position and posture information of the high-speed moving object. The purpose of matching in stereoscopic vision is effectively achieved through a colored stripe pseudorandom sequence and gray scale grid line phase position combined mode. A measurement system is low in cost, simple in mechanism and easy to operate.

A method for seismic prospecting that includes a step of deploying plural vibratory sources on the ground; a step of receiving at each vibratory source a corresponding pilot signal for driving the vibratory source; a step of asynchronously actuating the vibratory sources to generate seismic waves into the ground; and a step of continuously recording seismic signals produced by the seismic waves. Pilot signals for the plural vibratory sources are obtained by spectrally shaping starting sequences into continuous pseudorandom sequences that are weakly correlated over a predetermined time interval.