Integrated photonic RF self-interference cancellation on a silicon platform for full-duplex communication

In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation(PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference.Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and14.2 GHz, respectively, and the signal of interest(SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.

A review on the electric vehicle routing problems: Variants and algorithms

Over the past decade,electric vehicles(EVs)have been considered in a growing number of models and methods for vehicle routing problems(VRPs).This study presents a comprehensive survey of EV routing problems and their many variants.We only consider the problems in which each vehicle may visit multiple vertices and be recharged during the trip.The related literature can be roughly divided into nine classes:Electric traveling salesman problem,green VRP,electric VRP,mixed electric VRP,electric location routing problem,hybrid electric VRP,electric dial-a-ride problem,electric two-echelon VRP,and electric pickup and delivery problem.For each of these nine classes,we focus on reviewing the settings of problem variants and the algorithms used to obtain their solutions.

RF self-interference cancellation by using photonic technology [Invited]

Radio frequency(RF) self-interference is a key issue for the application of in-band full-duplex communication in beyond fifth generation and sixth generation communications.Compared with electronic technology, photonic technology has the advantages of wide bandwidth and high tuning precision, exhibiting great potential to realize high interference cancellation depth over broad band.In this paper, a comprehensive overview of photonic enabled RF self-interference cancellation(SIC)is presented.The operation principle of photonic RF SIC is introduced, and the advances in implementing photonic RF SIC according to the realization mechanism of phase reversal are summarized.For further realistic applications, the multipath RF SIC and the integrated photonic RF SIC are also surveyed.Finally, the challenges and opportunities of photonic RF SIC technology are discussed.