Sequence detection methods, devices, and systems for spectrum sensing in dynamic spectrum access networks

In one embodiment, a cognitive radio dynamic spectrum access sensing system is configured to incorporate a hidden Markov model and a risk function to determine the primary user state sequence with the minimum amount of associated risk. The system comprises one or more weighted cost factors that can be used to handle a missed detection sensing error differently from a false alarm sensing error. The system further comprises a complete forward partial backward computation designed to increase sensing accuracy with limited effect on sensing delay and complexity.