48results about How to "Good autocorrelation properties" patented technology

Small radio frequency tags for use in a motion capture system include a power source, circuitry for generating radio frequency identification signals, an antenna for transmitting the signals, and means for automatically activating the tags so that the tags begin transmitting the signals including a tag identification code when a cover is removed. The activation means may include a release strip that, when removed, opens or closes an electrical circuit that activates the tag and also exposes an adhesive covered surface of the tag so that the tag can then be adhered to a clothed or unclothed human body or other object to be tracked. The activation means can also include an optical sensor, an oxygen sensor, or other sensors. The battery and the antenna may be printed or constructed of film, thus allowing the tag to be small, thin, and flexible.

An improved generation and use of Positioning Reference Signals (PRS) are disclosed. The method generates PRS to be used in a wireless Orthogonal Frequency Division Multiplexing (OFDM) communication system. According to the invention, the method includes the steps of : - determining a time-frequency pattern of Resource Elements (REs) to be used for transmitting the PRS, wherein the time- frequency pattern includes at least two OFDM symbols, and - assigning, for each one of the at least two OFDM symbols, respectively, a value to each one of a number of the REs being within that OFDM symbol, wherein - the values being assigned to the number of REs correspond to elements in a modulation sequence having a length being equal to the number of REs, and are to be used for modulating OFDM subcarriers corresponding to the REs within that OFDM symbol.

The embodiment of the invention discloses a method, a device and a system for positioning user equipment. The method for positioning the user equipment provided by the embodiment of the invention comprises the following steps of: receiving a positioning signal which is sent by the user equipment and carries a ZC sequence or a CG sequence; and determining the position of the user equipment according to the positioning signal. By adopting the method, the device and the system, a frequency division multiple access (FDMA) system under long-term evolution architecture can accurately determine the position of the user equipment through a network. The embodiment of the invention also discloses a method for measuring arrival time, a method for sending the positioning signal, a base station and the user equipment.

The present invention provides a synchronization sequence transmission method, synchronization detection method and device. The transmission method includes: setting a target synchronization sequence with good autocorrelation characteristics; wherein, intercepting in the time domain or frequency domain of the target synchronization sequence The obtained at least one sequence is a sub-synchronization sequence, the sub-synchronization sequence has good autocorrelation characteristics and the sub-synchronization sequences have good cross-correlation characteristics; the target synchronization sequence is sent to the terminal; the embodiment of the present invention For terminals with different bandwidths or different carrier intervals, after the base station sends the same target synchronization sequence, the terminal can intercept the corresponding sub-synchronization sequence according to its own needs for synchronization detection, which not only ensures the accuracy of synchronization detection, but also improves the target Scope of application of the synchronization sequence.

The invention discloses a frequency domain arrival detection method of an orthogonal frequency division multiplexing system. A frequency domain synchronous transmitting unit adopts two frequency domain pseudorandom sequences with identical length but different phases, a zero is respectively compensated to each pseudorandom sequence to obtain a pseudorandom expanded sequence, then rapid Fourier inverse transformation operation is carried out on the pseudorandom expanded sequences to obtain time domain sequences, and then the two time domain sequences are cascaded to obtain a synchronous pilot training sequence. A frequency domain synchronous receiving unit adopts a time window with a length being identical to that of one pseudorandom expanded sequence, rapid Fourier transformation operation is carried out on data inside the window, then the data is correlated with a known local pseudorandom expanded sequence after being subjected to peak clipping and amplitude limitation processing, and the signal arrival is judged by utilizing excellent autocorrelation property of the pseudorandom sequence and simultaneously considering a threshold and position-based detection method. Due to the adoption of the frequency domain arrival detection method of the orthogonal frequency division multiplexing system, interference of a single tone, narrow band and the like can be effectively resisted, and reliable signal arrival detection can also be realized under a severe channel condition.

The invention discloses a high-speed burst signal synchronization and equalization device and method, and relates to the technical field of optical access. The device includes an equalizer, a time synchronizer and an equalization controller. The equalizer receives the uplink burst signal, and under the control of the equalizer controller, transmits the calculated equalized output to the time synchronizer in the blind equalization mode or the training equalization mode. Wherein, the PSBu data pattern of the uplink burst signal includes two parts, A+ and A-, which are negatively correlated. The time synchronizer finds the uplink burst signal based on the PSBu data mode, performs boundary identification, and feeds back to the equalizer controller. The equalization controller controls the equalizer to switch between the blind equalization mode and the training equalization mode according to the preset equalization control state machine according to the feedback. The present invention effectively combines the advantages of the two equalization modes, not only can efficiently equalize but also effectively guarantee the payload bandwidth of the system, and can also improve the quality of synchronization and training to meet the actual application requirements.