Spread spectrum modulation recognition based on phase diagram entropy

Spread-Spectrum Multi-h Modulation

Modulation Signal Recognition Based on Information Entropy and Ensemble Learning

In this paper, information entropy and ensemble learning based signal recognition theory and algorithms have been proposed. We have extracted 16 kinds of entropy features out of 9 types of modulated signals. The types of information entropy used are numerous, including Rényi entropy and energy entropy based on S Transform and Generalized S Transform. We have used three feature selection algorit...

Digital Modulation Recognition Based on Feature, Spectrum and Phase Analysis and its Testing with Disturbed Signals

The paper describes algorithm for the classification of digital modulations and testing of this algorithm with disturbed signals. 2ASK, 2FSK, 4FSK, MSK, BPSK, QPSK, 8PSK and 16QAM were chosen for recognition as the best-known digital modulations used in modern communication technologies. The algorithm is based on the evaluation of spectral power density of the normalized-centered instantaneous ...

Direct sequence spread spectrum Walsh-QPSK modulation

In this paper we present Walsh-quadrature phase-shift keying (Walsh-QPSK) pseudonoise (PN) modulation schemes for both coherent and noncoherent direct-sequence code-division multiple-access (DS-CDMA) systems, wherein the PN spreading sequences for in-phase and quadrature data in a conventional QPSK PN modulation scheme are coded by Walsh sequences indexed by a special rule to reduce the envelop...

Spatial image watermarking using spread spectrum modulation

The paper presents low cost spatial image watermarking scheme where inherent anti jamming and interference rejection property of spread spectrum modulation is utilized to provide robustness against image distortions and malicious attempts to remove or tamper with the watermark. The use of error correction code allows a trade-off between degree of robustness and embedding rate for a given attack...