Digital correlating appts. for e.g. radio astronomy - has parallel inputs with shift registers to receive data items and provides different correlation terms in counters

摘要

The appts. for forming a correlation function in relation to a stream of data items, for eg a one-bit auto-correlator for spectral analysis of an r.f signal, has storage devices, e.g shift registers (2,3) to which successive data items are directed in cyclic sequence. Exclusive-OR Multipliers (422-43m, 432-43m,8) form prods. of the data items in their associated storage devices and these prods. are combined by multiplexers (62-6m, 14) to form the different correlation terms in counters (7,15). By using storage devices in parallel, the reqd. speeds of operation of the appts. may be reduced. The two registers are clocked by different clock phases. Counters (9,10) and associated switches (11,12) are clocked by different clock phases to provide delay to prod. the odd order terms, multipliers producing the even order terms.