4 ms·
also FYI: so called "golden codes" that are used to modulate GPS information bitstream are also bunch of LFSR counters and chosen in such a way that the whole s
by artemonster 3y ago
also FYI: so called "golden codes" that are used to modulate GPS information bitstream are also bunch of LFSR counters and chosen in such a way that the whole set of them (around 30? dotn remember) has a very low correlation factor between them
- willis936 3y agoThis is how PRBS works more generally. It's in everything. Use the same factors and set the start point. Iiuc what you're describing is using different sets of factors, which would guarantee low correlation, if differing spectra. https://en.wikipedia.org/wiki/Pseudorandom_binary_sequence https://en.wikipedia.org/wiki/Pseudorandom_binary_sequence
- kurthr 3y agoYes, for LFSRs it is often the high ratio of auto/cross correlation for the particular encode phase, along with the ease of generation and deconvolution for single bit signaling at low SNR. I don't know that most other pseudo-random codes have this property.
- andyjohnson0 3y ago> so called "golden codes" A minor point, but they are called Gold codes -- after Robert Gold, who developed the technique in the 60s. https://en.wikipedia.org/wiki/Gold_code https://en.wikipedia.org/wiki/Gold_code
- kurthr 3y agoThere are also the related Kasami codes. Both are made by selecting uncorrelated LFSR sequences and combining them. That has the advantage of extending code length, while maintaining cross-correlation and whiteness properties. Really helpful in early error correction.