> The fact that spreading factors are orthogonal as well is also pretty impressive This has been quite standard for 20+ years. For instance 3G spreading codewo

> The fact that spreading factors are orthogonal as well is also pretty impressive This has been quite standard for 20+ years. For instance 3G spreading codewords are also orthogonal. If fact, I think LoRa took a lot from mobile/cellular where all those technics have been used for a long time. Edit: As used in 3G, the orthogonal spreading codewords (OVSF) are actually quite simple to generate for a given spreading factor: https://www.mathworks.com/help/comm/ref/ovsfcodegenerator.html https://www.mathworks.com/help/comm/ref/ovsfcodegenerator.ht...