Lingna Holdings Pte., LLC

Dynamic Invention LLC

Ke Lin Du

Wai Ho Mow

Wei Hsiang Wu

Spectrum sensing in wireless communications is provided to identify utilized and/or unutilized frequency bands reserved for primary users using a cyclostationary beamforming approach. An adaptive cross self-coherent restoral (ACS) algorithm can be utilized to extract signals of interest (SOI) at unique cycle frequencies related to primary and/or secondary users from an antenna array measurement. Based on the SOI, one or more users of the spectrum can be identified or the spectrum can be regarded as vacant; this can be based on lobe identification in the frequency spectrum of the SOI, in one example. This mechanism is less complex than traditional cyclic spectrum analysis methods. The cyclostationary beamforming based approach is more effective than the energy detection method. Also, the need for quiet periods in spectrum sensing is eliminated when using this mechanism such that signals can be transmitted simultaneously with receiving signals over the antenna array.

Exploiting multiple antennas for spectrum sensing in cognitive radio networks

Systems, methods, and computer-readable media for determining long binary sequences having low autocorrelation functions using evolutionary processes are disclosed. Biphase sequences are found with low peak sidelobe values meeting a predetermined criterion, e.g., threshold low auto-correlation function, including application of semidefinite programming in connection with determining an initial population, and evolving the population with an evolutionary algorithm to bits of the biphase sequences including bit flipping. The found biphase sequences can be communicated to a variety of applications, including wireless communications technologies.

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Verdun, Canada

Ke Lin Du