摘要:
A method of detecting transient changes in the distribution of a discrete time series includes: operating in a sparse mode wherein, at sniff periods successively repeated at a first rate, at most K test phases are performed, K being an integer superior or equal to two, each test phase consisting of analyzing, by a sampling stopping time determination unit, samples of the time series captured by a sampler at sampling times according to a second rate which is higher than the first rate to provide a positive or negative result of the test phase. If the results of K successive test phases of a sniff period are each positive, the method switches to operate in a dense mode wherein the sampler is operated to continuously capture samples of the time series at sampling times according to the second sampling rate.
摘要:
A wireless communication device is provided to carry out correlation peak detection processing properly and efficiently in intermittent receiving unit. If a correlation peak is not detected in a first period in which a correlation peak detecting unit (22) detects the correlation peak at a default frequency and a first frequency in a detecting period of a coarse frequency deviation detecting unit (23) in the first period, a control unit (25) makes the correlation peak detecting unit (22) carry out the peak detection at the first frequency in a second period. If the correlation peak is detected in the correlation peak detecting unit (22) and a second frequency is detected in a detecting period of a fine frequency deviation detecting unit (24) in the first period, the control unit (25) makes the correlation peak detecting unit (22) carry out the peak detection at the first and second frequencies in a third period.
摘要:
A DSSS detector (19) for detecting a synchronization between an aperiodic spread spectrum signal (r(nT c )) having a plurality of chips (r(n) ) and a spreading sequence (PN) having a plurality of chips (pi). The DSSS detector (19) has at least one branch (16) adapted to receive the spread spectrum signal, and the branch is formed by a plurality of correlators (1) cascade connected to each other and separated one another by a branch delay block (20). Each correlator (1) has a multiplier (12) for correlating chips (pi) of the spreading sequence (PN) with chips (r(n) ) of the spread spectrum signal (r(nT c )) and generating each an own correlation value (y(n)). The DSSS detector (19) further has a matching detector (22, 23, 27) receiving the correlation values (y(n) ) and detecting when all the correlation values (y(n)) are maximum.
摘要:
The invention relates to a device (11) for carrying out a correlation, comprising a data memory (12) for storing a sequence of sampling values (110), an address generator (13) for generating addresses in order to read out a data word (111), whereby the sequence of the sampling values in the data word (111) must not be chronological; a code generator (15) for generating a correlation word (112) from sequence elements of a correlation sequence, whereby the sequence elements in the correlation word (112) are arranged in a sequence according to the data word (111); and a correlator unit (14).