Transmission signal generating/detecting method by using code sequences, communication system using the same and measurement system using the same

Abstract

The present invention provides a transmission method which generates and sends a transmission signal generated from a multiplexing OFDM signal or a multiplexing wavelet-OFDM signal employing a multiplexing-spread chip sequence in which a chip of a code sequence for spread and a code sequence for combination, and a chip of a code sequence for localization are multiplied and multiplexed, and a receiving method which makes a high SN ratio improvement rate possible by converting the received signal to a frequency domain to acquire the multiplexing-spread chip sequence and by performing de-spreading and localizing processing to detect a localized pulse. According to the data transmission using the transmission and receiving method, data is mapped into a code sequence, and the receiving side can detect the data as the kind of code sequence, the shift time of a localized pulse and the polarity at a high SN ratio improvement rate. Further, when used in a measuring system, the transmission and receiving method can obtain information associated with an object to be measured on the basis of the aspect and the characteristics of a localized pulse by calculating the localized pulse from a signal detected from the object to be measured at a high SN ratio improvement rate.

Description

technical field [0001] The present invention relates to a transmission signal generation / detection method using a code sequence, a communication system using the method, and a measurement system using the method. Background technique [0002] In order to build a smart grid, etc., a communication method that realizes high-speed, high-quality communication in the presence of strong noise and obstacles is required. At present, the Direct-Sequence Spread Spectrum (DS-SS, Direct-Sequence Spread-Spectrum) method has been disclosed, which is a communication method with excellent anti-noise characteristics and capable of realizing multiple access. However, although this method can pass De-spreading and removing narrow-band noise superimposed on the transmission signal in such a way that communication is performed outside the bandwidth improves the SNR, but it has a problem that it cannot improve the SNR of broadband noise (Non-Patent Document 1 ,2). [0003] The following transmis...

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Problems solved by technology

[0004] Also disclosed are the following M-ary methods aimed at fast transmission and multi-valued M-ary methods for expressing data with a combination of multiple code sequences and polarity, however, these methods have such The problem is that the improvement rate of the SN ratio of each method is equal to or less than that of the DS-SS method, and in the case of the multi-valued M-ary method, it is difficult to detect each M-ary signal, so it is difficult to increase the multiplicity ( multiplicity) to obtain sufficient transmission speed (non-patent literature 1, 3, 4)

[0005] Also disclosed are code sequence type transmission devices and reception devices (Patent Documents 1, 2, 3), which use multiplexed basic pulse trains (which are data with The extended code sequence applied to the period of the period is multiplied by the order pulse train (oder pulse train) composed of the extended code pulses of the period and multiplexed) to generate the transmission signal, and the transmission signal is sequentially generated by using the order pulse train. The detected multiplexed elementary bursts are despread to decode the data, thereby demultiplexing the low-speed code sequences and detecting their localized bursts, however, there is the problem that the spreading code sequences of this technique only provide order , the data is only mapped to the code sequence with extension applied, the amount of information per slice is therefore small, and although an acceleration scheme is obtained by multiplexing the basic bursts to compensate for this shortcoming, this acceleration scheme requires a long time period for processing and complicate the circuit, resulting in an increase in cost

In addition, the S / N ratio is improved by despreading the periodic elementary bursts based on sequential bursts and localizing the signal undergoing despreading, however, there is also the problem that despreading involves applying despreading The period of the code sequence of the basic burst is used as the unit, so the expansion rate cannot be obtained sufficiently, which leads to the limitation of the improvement rate of the SN ratio, and the acceleration scheme is constrained

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