Simulation of the Radio Communication Channel with Unmanned Aerial Vehicle in Urban Conditions
Gennady Kulikov,
Alexander Nesterov,
Andrey Leluh
Issue:
Volume 6, Issue 4, August 2018
Pages:
104-110
Received:
31 July 2018
Accepted:
23 August 2018
Published:
13 October 2018
Abstract: Modern unmanned aerial vehicles (UAVs) are used in many spheres of human activity. In conditions of strong urban development, the radio communication channel with UAV is multi-path, which leads to a significant decrease in the quality of the transfer of useful information. Ensuring reliable and qualitative communication depends on the correct choice of the frequency range and the type of modulation used. Multiposition signals of M-PSK, M-QAM, M-FSK formats are considered. Due to the complexity of the mathematical description of such a radio channel, a computer simulation method was used to obtain the results. A multipath propagation model with a number of beams up to 10 is used. The dependencies of the probability of erroneous reception of information on the parameters of the communication channel are obtained: the signal-to-noise ratio, the number and intensity of the propagation paths. The energy parameters of the radio channel are calculated and the optimal frequency range is estimated from the maximum signal-to-noise ratio. It is indicated that the best in this criterion is the operating frequency range of 2-5 GHz. Calculations showed that the transmission coefficient of the radio channel is unstable and varies greatly in frequency. When using narrow-band signals M-PSK, M-QAM, this can lead to a situation where the signal can get into the "bad" frequency band and the quality of information transfer will decrease significantly. In connection with this, a radio channel with multiposition frequency modulation M-FSK was studied, when the transmission of discrete information is carried out using multiple parcels with different frequencies falling into both "bad" and "good" frequency zones. The results of the study showed that the probability of BER error in some cases improves by times compared to M-PSK and M-QAM. This allows us to talk about the prospects for the M-FSK format. Considering the good performance of this format, further studies are planned in the direction of using M-FSK format signals and their prospective version of M-CPFSK (multi-position frequency modulated signals with a continuous phase) in the considered radio channel with different modulation and positioning indices, in particular CPFSK with modulation indices of 0.5 and 0.75, together with MIMO and OFDM systems. The obtained results can be used in the design of modern and promising UAV-to-ground communication systems.
Abstract: Modern unmanned aerial vehicles (UAVs) are used in many spheres of human activity. In conditions of strong urban development, the radio communication channel with UAV is multi-path, which leads to a significant decrease in the quality of the transfer of useful information. Ensuring reliable and qualitative communication depends on the correct choic...
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Comparison of RFIC PA Die and Laminate Co-Simulation Methods
Liu Xilei,
Dai Dajie,
Chen Sidi,
Yang Hanbing,
Li Xuejian,
Zhou Xianhua,
Yue Bingdi
Issue:
Volume 6, Issue 4, August 2018
Pages:
111-119
Received:
18 September 2018
Accepted:
30 September 2018
Published:
29 October 2018
Abstract: Package (such as LGA, MCM etc.) with main circuits on Die(s) situated on a substrate and with OMN in the substrate laminate is one of the most popular design styles for RFIC PAs in recent times. In practical design, the overall circuit of the RFIC PA is often designed using ADS Schematic simulation tool. The main circuit is then layout for Die design, and the OMN circuit is layout for laminate design. As the actual parasitics associated with the real RF circuits with high packing dense have significant effects on the RFIC performance, the traditional closed-form circuit models may be no longer valid, and co-simulations of the Die circuit or Die layout EM model and the laminate layout EM model are often considered in order to improve simulation accuracy. There are some generally considered co-simulation methods in practical design, such as Die circuit + Laminate Momentum, Die circuit +Laminate HFSS, Die layout Momentum +Laminate Momentum, Die layout Momentum +Laminate HFSS, Die layout +Laminate ADS Nested Technology, etc. Design engineers might be confused about which co-simulation methods should take for RFIC PA design and development. This paper reviews, compares and discusses the above co-simulation methods in the aspects of algorithms of the simulators, co-simulation modeling method, complexity to build model, run time, and the difference between simulation and measurement results by giving an example of a self-developed RFIC PA operating at 2GHz. It endeavors to draw helpful conclusions for simulation experiences in practical RFIC PA design, and a co-simulation method with Die layout Momentum EM model +Laminate HFSS EM model is recommended based on the software versions used in this work.
Abstract: Package (such as LGA, MCM etc.) with main circuits on Die(s) situated on a substrate and with OMN in the substrate laminate is one of the most popular design styles for RFIC PAs in recent times. In practical design, the overall circuit of the RFIC PA is often designed using ADS Schematic simulation tool. The main circuit is then layout for Die desi...
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