Shuangde Li

Study on the multipath propagation characteristics of UWB signal for indoor lab environments

The propagation characteristics of ultra-wideband (UWB) signal have been a popular topic in wireless communications with the advantages of large bandwidth and high communication rate. This paper studies on the multipath propagation characteristics of UWB signal for indoor laboratory environment by time domain ray tracing method. Also, reflection, diffraction, transmission and direct rays are all considered. Firstly, the validity of simulation based on time domain ray tracing method is proved. Then, in order to research on the multipath propagation characteristics, the root-mean-square (RMS) delay spread and path loss are analyzed by simulation. Later, the study can provide the theoretical basis for wireless communication network coverage and optimization of UWB signal in indoor environments.

Measurements and modelling of millimeter-wave channel at 28 GHz in the indoor complex environment for 5G radio systems

This paper presents an experimental characterization of millimeter wave (mmWave) wireless channel at 28 GHz for fifth generation (5G) millimeter wave wireless communication systems. The propagation characteristics of mmWave signal in the complex indoor radio channels are discussed based on the extensive measurement and based on the method of shooting and bouncing ray tracing/image (SBR/IM). Received power, omnidirectional path loss models, and root-mean-square (RMS) delay spreads statistics are analyzed. A good agreement is achieved between measured results and simulated results, so a method for synthesizing the omnidirectional antenna pattern and resulting omnidirectional received power from empirical data using directional horn antenna by summing the received powers from each angle combination has been validated. The cumulative distribution function (CDF) of received power can be described by the log-normal distribution. Moreover, the path loss exponent (PLE) values vary between 1.67 and 1.77. The Gaussian distribution models best fit the RMS delay spreads at 28 GHz.

Study on the outdoor wave propagation at 28GHz by ray tracing method

Based on the ray tracing method, the outdoor propagation characteristic at 28GHz are simulated and analyzed by comparison with the conventional 2.6GHz cellular band. The path loss is discussed in both line-of-sight and none-line-of-sight, and then the delay spread is analyzed at 28GHz and 2.6GHz. The analysis provides the foundation for the coverage of outdoor microcellular systems.

Simulation and analysis of 60GHz millimeter-wave propagation characteristics in indoor complex environment

The 60GHz band millimeter-wave propagation characteristics are simulated and analyzed using the method of ray tracing method in the indoor complex environment. The propagation characteristics in the line-of-sight(LOS) and non-line-of-sight(NLOS) environment are discussed. The effect of the polarization and the roughness on the root-mean-square(RMS) delay spread are analyzed. Results of the study can provide a theoretical basis for the coverage planning on indoor wireless networks.

Simulation and analysis of indoor propagation characteristics for UWB based on TD-UTD

In this paper, the propagation characteristics of UWB signal in the typical indoor complex environment are discussed based on the time-domain uniform theory of diffraction (TD-UTD). Some propagation parameters are analyzed by considering of multipath propagation mechanisms including direct ray, reflection, diffraction and transmission, such as received waveform, power delay profile, distribution of the direction angle of arrival and so on. The results show that: (1) Horizontally polarized rays contribute more energy than vertically polarized rays. (2) For the given environment, the high order reflection are weak and can be ignored. (3) The statistical distribution of arrival angle in the complex indoor environment have demonstrated that in order to improve the efficiency of the receiving point, the vertical polarization antenna is recommended. These results provide the theoretical basis for wireless communication network coverage and optimization of UWB signal in the complex environment of indoor.

Study on the multipath propagation model of UWB signal in the indoor environment based on TD-UTD

In this paper, the propagation characteristics of UWB signal in the indoor complex environment are discussed based on the time domain uniform theory of diffraction (TD-UTD). A number of propagation parameters are analyzed by considering of multipath propagation mechanisms including direct ray, reflection, diffraction and transmission, such as the time-domain normalized electric field intensity, power delay profile, and so on. The results show that: (1) The direction path is the first to arrive the receiving point and it is the strongest signal in LOS (Line of Sight). (2) The multi-reflection, diffraction and transmission are important in NLOS (Non Line of Sight). For low loss medium wall, the transmission signal has strong power and cannot be ignored. These results provide the theoretical basis for wireless communication network coverage and optimization of UWB signal in the complex environment of indoor.

Channel Measurements and Modeling at 6 GHz in the Tunnel Environments for 5G Wireless Systems

Propagation measurements of wireless channels performed in the tunnel environments at 6 GHz are presented in this paper. Propagation characteristics are simulated and analyzed based on the method of shooting and bouncing ray tracing/image (SBR/IM). A good agreement is achieved between the measured results and simulated results, so the correctness of SBR/IM method has been validated. The measured results and simulated results are analyzed in terms of path loss models, received power, root mean square (RMS) delay spread, Ricean K-factor, and angle of arrival (AOA). The omnidirectional path loss models are characterized based on close-in (CI) free-space reference distance model and the alpha-beta-gamma (ABG) model. Path loss exponents (PLEs) are 1.50–1.74 in line-of-sight (LOS) scenarios and 2.18–2.20 in non-line-of-sight (NLOS) scenarios. Results show that CI model with the reference distance of 1 m provides more accuracy and stability in tunnel scenarios. The RMS delay spread values vary between 2.77 ns and 18.76 ns. Specially, the Poisson distribution best fits the measured data of RMS delay spreads for LOS scenarios and the Gaussian distribution best fits the measured data of RMS delay spreads for NLOS scenarios. Moreover, the normal distribution provides good fits to the Ricean K-factor. The analysis of the abovementioned results from channel measurements and simulations may be utilized for the design of wireless communications of future 5G radio systems at 6 GHz.

Simulation and analysis of multipath propagation characteristics for UWB in the indoor radio channels based on SBR/IM

In this paper, the propagation characteristics of UWB (Ultra-wideband) signal in the indoor radio channels are discussed based on the method of SBR/IM (Shooting and bouncing ray tracing/image). Propagation characteristics are analyzed by considering of multipath propagation mechanisms including direct ray, reflection and transmission. A good agreement is achieved between the measured results and simulated results, so the correctness of the SBR/IM method has been validated. Some channel propagation characteristic parameters of UWB are discussed in the simulated results, such as values of the path loss, the distribution of the received power, the time-domain electric field intensity. Also, path loss exponent is deduced from the simulated results. The analysis of the above results may be provide the theoretical basis for wireless communication network coverage and optimization of UWB signal in the complex environment of indoor.

Simulation of 38 GHz millimeter-wave propagation characteristics in the indoor environment

In this paper, the propagation characteristics of 38GHz millimeter wave in an indoor environment are simulated based on ray tracing method. The path loss and delay spread are discussed and analyzed on both line of sight and non line of sight. The conclusions drawn in this thesis may be utilized for the design of millimeter-wave mobile communications for the future fifth generation cellular system.

Simulation and analysis of indoor millimeter-wave propagation based on the ray tracing method

Ray tracing method is an effective way to study radio propagation. In this paper, the indoor millimeter-wave propagation at 37.2GHz is simulated and analyzed by the ray tracing method. By comparison with reported measurement results, the validity of the ray tracing method is verified and analyzed, and then the propagation characteristic at 37.2GHz is studied under the different transmitted antenna.