Broadband Cognitive Radio Enabled by Photonics

Abstract

Cognitive radio is considered as a possible disruptive force to improve the spectral resource efficiency through sensing and interacting with the environment. Traditional electrical technologies to implement the cognitive radio face challenges in terms of bandwidth, resolution, and speed. In this paper, the concept and architecture of broadband cognitive radio systems enabled by photonics are proposed. Key microwave photonic techniques for the architecture are reviewed, including the photonics-based spectrum sensing, the photonic arbitrary waveform generation, the photonics-based self-interference cancellation processing, and the microwave photonic dechirp processing and radar imaging. A preliminary demonstration of a cognitive radar system enabled by photonics is performed. The future possible research directions on this topic are discussed.

Photonic-assisted microwave frequency measurement towards cognitive radio

“…Electronic warfare (EW) is the only discipline operating in the electromagnetic spectrum in the observe and the act stages 1 . An available frequency operating range has become scarce, due to the increasingly demand of wireless devices and electromagnetic systems.…”

“…(1) (2) in which: Γ = the insertion power loss of the link; J n = the n-th order Bessel function of the first kind; m=πV rf / V π = the modulation index, being V rf the RF signal amplitude and V π the DD-MZM half-wave voltage. The complex coefficients a n (1) and a n (2) are expressed as Eqs. 3 and 4:…”

“…Then, the information is processed and oriented, enabling a decision making. Finally, it becomes an act when configuring the transceiver in a proper way 1 .…”

Microwave Photonic Channelizer With Large Instantaneous Bandwidth Based on AOFS

“…ITH the rapid development of broadband wireless communications, radar systems, and electronic warfare, the requirement of reception capability for ultra wideband radio frequency (RF) signals is also increasing [1]- [9]. For example, the military receiver proposed by the US Defense Advanced Research Projects Agency (DARPA) requires that the working bandwidth must be greater than 50 GHz, and the instantaneous bandwidth greater than 5 GHz [7] . However, the traditional microwave receiver is limited by the electronic bottleneck and it is too difficult to achieve such an large instantaneous receiving bandwidth [4]- [15].…”

Photonics‐based de‐chirp processor with the capability of processing dual‐band signals

“…De-chirp processing of dual-band signals (X-and Ku-band) is successfully implemented. The crosstalk suppression ratio of more than 40 dB is achieved with de-chirped results in the two bands.Introduction: In order to achieve the cognition ability to learn, infer and react to the environment, multiple functions working in different optimal frequency bands are required with the future radar systems [1][2][3][4]. The limitations in the working frequency and bandwidth bring a great challenge to the electronic technologies.…”