| 摘要 |
1517170 Pseudo-random pulse sequence generators LICENTIA PATENT VERWALTUNGS GmbH 30 Oct 1975 [31 Oct 1974] 45003/75 Heading G4D The invention relates to a way of producing very long pseudo-random pulse sequences. As described a first generator S.F.G. provides a plurality of trains of binary digits to a collator Z1. The collator comprises (Fig. 6.1, not shown) a plurality of controlled switching circuits which select which of the input trains is applied to which of a plurality of output lines. A second generator S.R.G.1 comprises one or more shift registers S.R. with feedback from selected stages to the first to generate pseudo-random trains in the usual way. The outputs of the collator are applied to modify the trains in the or each shift register. The outputs of the shift registers may be applied to a further collator Z2 whose output similarly modifies the trains from further feedback shift registers S.R.5, 6 whose outputs are then combined to provide the final long sequence. Alternatively (Figs. 7.1, 7.2, not shown) the outputs of S.R.G.1 may be combined to provide the final sequence. The first generator S.F.G. may comprise a multistage counter (Fig. 2, not shown) which repeated counts clock pulses to a preselected number or it may be another feedback shift register. The shift registers S.R.1-S.R.6 may have modifying inputs applied to more than one stage (Fig. 4, not shown) or the group S.R.1- S.R. 4 may be replaced by a single register with inputs to several stages. Variables in all stages are controlled by two classes of signal s and p. The p signals are derived from a programme and are fixed for a run while the s signals are derived from elsewhere in the system and thus continually charge. The s signals are not all the same but are interchangeable. These signals may vary the count in generator S.F.G., the selections made by the collators Z1, Z2 and the effective length and feedback paths of the shift registers; they may also be added into the pulse sequence at any stage. The final sequence can be made even more random by connecting the collators Z1, Z2 through code converters (Fig. 6.2, not shown). |
