Tunable K/W-band OFDM integrated radar and communication system based on optoelectronic oscillator for intelligent transportation.

In this paper, we proposed a tunable K/W-band OFDM integrated radar and communication system based on Optoelectronic Oscillator (OEO) for intelligent transportation. All-optical signal processing including amplitude asymmetric filtering and quadratic phase manipulating is applied in OEO to achieve a high-frequency and tunable self-excited oscillation, which supports the K/W-band OFDM signal generation. Its product of maximum detection range and communication capacity is cB/4Δf (m·Gbaud), where c is light speed and Δf is subcarrier spacing of OFDM. A proof-of-concept experiment is carried out in K-band with bandwidth B = 2 GHz and W-band with bandwidth B = 10 GHz. The range resolution ΔR, detection range Rmax and communication capacity C of 0.075 m, 75 m, 12.8 Gbps, and 0.015 m, 300 m, 32 Gbps are experimentally demonstrated in K/W-band respectively.

Reconfigurable radar signal generator based on phase-quantized photonic digital-to-analog conversion.

A novel, to the best of our knowledge, scheme for reconfigurable radar signal generation is proposed based on the principle of photonic phase-quantized digital-to-analog conversion. Multi-level digital phase modulation with different modulation depths is combined to convert multi-channel digital data to the phase of an optical carrier. Frequency-modulated or phase-modulated radar signals are generated by beating the phase-synthesized optical carrier with a coherent reference light. The proposed radar signal generator features a simple structure, highly reconfigurable modulation format, and flexibly tunable frequency. A 3-bit photonic phase-quantized digital-to-analog converter with a 10-GSa/s sampling rate is constructed experimentally. The generation of linear frequency-modulated, nonlinear frequency-modulated, frequency-stepped, frequency-hopping, binary phase-coded, and polyphase-coded waveforms is demonstrated.

Photonics-assisted joint radar and communication system based on an optoelectronic oscillator.

This paper reports a photonics-assisted joint radar and communication system for intelligent transportation based on an optoelectronic oscillator (OEO). By manipulating the optical multi-dimensional processing module inserted in the OEO loop, two phase-orthogonal integrated signals are generated with low phase noise and high frequency, as the communication data loaded on the overall polarity of radar pulses. At the receiver, single-channel matched filtering and two-channel IQ data fusion are utilized to retrieve the communication data and the range profile, without any performance deterioration of either. In this way, the contradiction between the performance of two functions existing in the previous scheme is solved, and the integrated performance can be further optimized as bandwidth increases. A proof-of-concept experiment with 2 GHz bandwidth at 24 GHz, which is the operating frequency of short-range automotive radar, is carried out to verify that the proposed system can meet the requirement of the intelligent vehicles in the short-range scene. A communication capacity of 335.6 Mbps, a range profile with a resolution of 0.075 m, and a peak-to-sidelobe ratio (PSLR) of 20 dB is demonstrated under the experimental condition. The error vector magnitude (EVM) curve and constellation diagrams versus received power are measured, where the EVM is -8 and -14.5 dB corresponding to a power of -14 and 6 dBm, respectively.

Hypoglycemic effects of polysaccharides from Gomphidiaceae rutilus fruiting bodies and their mechanisms.

Insulin resistance is the main cause of type 2 diabetes, fatty liver and obesity. Our previous study found that mushroom polysaccharides improved insulin resistance in vitro, but the underlying mechanisms were still unknown. Thus, we investigate the hypoglycemic effects of polysaccharides from Gomphidiaceae rutilus fruiting bodies and their mechanisms. The total polysaccharides (AGRP) from Gomphidiaceae rutilus fruiting bodies and the neutral polysaccharide (AGRP-N) fraction both enhance insulin-stimulated glucose uptake in an autophagy-dependent manner in high glucose and fatty acid-treated hepatic cells, but not the acidic polysaccharide (AGRP-A) fraction. Further, we elucidate the oral hypoglycemic effects of polysaccharides on ob/ob mice. AGRP and AGRP-N lower blood glucose and improve insulin sensitivity. They inhibit liver lipid deposition, not only by activating AMPK to increase autophagy but also by increasing the expressions of PPARα and CPT-1a to enhance lipolysis. Our results provide a basis for the development of polysaccharides from Gomphidiaceae rutilus as a hypoglycemic healthy food.

Polysaccharide-Enriched Fraction from Amillariella Mellea Fruiting Body Improves Insulin Resistance.

Despite the edible fungus Amillariella mellea possessing a variety of biological activities, its effects on diabetes are still unclear. Polysaccharides are the main bioactive ingredients. In order to destroy the cell wall to obtain more polysaccharides, we used NaOH solution to extract Amillariella mellea fruiting bodies. The alkali extraction (AAMP) was identified as a polysaccharide-enriched fraction. Using type 2 diabetic rats induced by co-treatment of a high fat diet (HFD) and dexamethasone (DEX), we evaluated the hypoglycemic effects of AAMP. The results showed that oral administration of a high dose of AAMP markedly lowered fasting blood glucose, improving glucose intolerance and insulin resistance. AAMP also enhanced the level of LPL and the expressions of two critical lipases ATGL and HSL, leading to a decrease of serum triglyceride. In addition, AAMP specifically suppressed the expression of SREBP-1c, resulting in AAMP observably inhibiting lipid accumulation in the liver. These findings demonstrated that the improvement of AAMP on HFD/DEX-induced insulin resistance was correlated with its regulation of lipid metabolism. Our results indicated that AAMP could be a novel natural drug or health food used for the treatment of diabetes.