The research on the substitution effect between the wireless and fixed telecommunication industry

Wireless telecommunication has developed at a rapid pace than the fixed telecommunication since the last decades of twentieth century. This article analyzes the effect wireless mobile telecom substitutes for the fixed telecom by employing the normal theory of substitution and econometrics model. The analytical results are consistent with the reality, and it has been observed that the relation between the wireless and fixed telecommunication industry has changed from state of being complementary in the early last decades of twentieth century to that of being substituted at present. Moreover, the enhanced progress of telecommunication technology especially in wireless areas enriches customers＇ demands in terms of multimedia contents thereby changing their communication style, which significantly promotes the rapid growth of wireless mobile communication and strengthens the effect of the substitute.

A novel technique for wireless optical communications with lenslet array processor

A novel communication technique is proposed, which utilizes a set of mutually distinguishable optical patterns instead of convergent facula to transmit information. Then the capacity is increased by exploiting the optical spatial bandwidth resources. At last, we experimentally demonstrate the proposed communication technique based on four 8 × 8 spatial pattern signals by using lenslet array processor.

Time domain dispersion of underwater optical wireless communication

A new method to count the expected value and variance of time dispersion is presented for time dispersion of underwater optical wireless communication.Instead of the typically used Gamma distribution,inverseGaussian distribution is suggested for underwater optical impulse response time waveform function.The expectation of this method is in good agreement with experimental data.Future works may include water absorption to the model.

20 Mbps wireless communication demonstration using terahertz quantum devices

A wireless terahertz （THz） communication link is demonstrated, in which a THz quantum cascade laser and a THz quantum-well photo-detector （QWP） serve as the emitter and receiver, respectively. With the help of the well-matched THz QWP, the optical collection efficiency has greatly been improved. A data signal transmitted over 2.2 m with a low bit error rate （≤1 × 10^-8） and data rate as high as 20 Mbps is achieved, which are almost 1 order of magnitude higher than that previously reported.

UWB monocycle pulse generation based on optical cross-polarization modulation

A novel all-optical method for ultra-wideband （UWB） monocycle pulses generation based on cross polarization modulation （CPM） effect in highly nonlinear photonic crystal fiber is proposed and demonstrated. Due to the CPM effect between the probe light and the pump pulse, a pair of polarity-reversed Gaussian pulses is produced. After proper differential delay, an UWB monocycle pulse with 84-ps width and the fractional bandwidth of 153% is generated after photodetection.

Spread spectrum-based ultraviolet communication with experiments

We report experiments of ultraviolet （UV） communication based on spread-spectrum technique. Field measurements via online UV communication are conducted to compare the system performances with and without spectrum spreading. The results indicate that the spread-spectrum technique is capable of suppressing noise in UV atmospheric scattering channel and therefore improve the system performance evidently. Details of implementation are also provided to make the results useful for similar system design in research on optical wireless communications.

Indoor multi-robot intelligent coordination based on omni-directional visible light communication

Multi-robot coordination （MRC） is a key challenge for complex artificial intelligence systems, and conventional wireless-communication-based MRC mechanisms that cannot be deployed in radio-frequency-limited environ- ments. In this Letter, we present a promising solution that utilizes indoor omni-directional visible light communication （VLC） technology to realize efficient multi-robot intelligent coordination （MRIC）. The specific design is presented along with the implemental details of a practical MRIC experimental platform. The exper- imental results show that a 50 Mb/s on-off-keying-based omni-directional VLC can be realized with an effective distance of 2.3 m and a bit error rate of 〈10^-6 in the proposed MRIC platform.