Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient co...Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient connection among IIoT devices,CRNs enhance spectrum utilization by using licensed spectrum.However,the routing protocol in these networks is considered one of the main problems due to node mobility and time-variant channel selection.Specifically,the channel selection for routing protocol is indispensable in CRNs to provide an adequate adaptation to the Primary User(PU)activity and create a robust routing path.This study aims to construct a robust routing path by minimizing PU interference and routing delay to maximize throughput within the IIoT domain.Thus,a generic routing framework from a cross-layer perspective is investigated that intends to share the information resources by exploiting a recently proposed method,namely,Channel Availability Probability.Moreover,a novel cross-layer-oriented routing protocol is proposed by using a time-variant channel estimation technique.This protocol combines lower layer(Physical layer and Data Link layer)sensing that is derived from the channel estimation model.Also,it periodically updates and stores the routing table for optimal route decision-making.Moreover,in order to achieve higher throughput and lower delay,a new routing metric is presented.To evaluate the performance of the proposed protocol,network simulations have been conducted and also compared to the widely used routing protocols,as a benchmark.The simulation results of different routing scenarios demonstrate that our proposed solution outperforms the existing protocols in terms of the standard network performance metrics involving packet delivery ratio(with an improved margin of around 5–20%approximately)under varying numbers of PUs and cognitive users in Mobile Cognitive Radio Networks(MCRNs).Moreover,the cross-layer routing protocol successfully achieves high routing performance in finding a robust route,selecting the high channel stability,and reducing the probability of PU interference for continued communication.展开更多
In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determin...In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determined by the average delay profile and the Doppler spectra. The profile characteristics and their influences on channel behavior are also examined.展开更多
That making phone calls had nothing to do with lightning strike was proved from the aspects of radio wave characteristics,receiving and transmitting frequency,power as well as the electromagnetic induction of mobile p...That making phone calls had nothing to do with lightning strike was proved from the aspects of radio wave characteristics,receiving and transmitting frequency,power as well as the electromagnetic induction of mobile phones. And through assuming mobile phone could trigger lightning,the probable death toll disproved the absurdity of mobile phone triggered lightning. And we concluded that making phone calls in thundery days would not increase the probability of lightning stroke,and calls could be made in thundery days as long as in the safe position.展开更多
A new method for the coverage prediction of Cellular Mobile Radio (CMR) system is developed and its basic principle is presented. Unlike the Statistical Prediction Model (SPM) that estimates propagation loss by empiri...A new method for the coverage prediction of Cellular Mobile Radio (CMR) system is developed and its basic principle is presented. Unlike the Statistical Prediction Model (SPM) that estimates propagation loss by empirical formulas or the Deterministic Prediction Model (DPM) that reckons propagation loss with analytical expressions, the Radio Computerized Tomography (RCT) method does not seek to express the propagation loss explicitly. The 2 D distribution of propagation loss factor is computed using CT technique, based on measured data collected through drive test under appropriate geometric constraint. The total propagation loss can be obtained by integral of propagation loss factor along the equivalent ray path. The advantages and limitations of the technique, as well as its implementation are discussed.展开更多
We study on the implementation flow of the radio computerized tomography (RCT) prediction method. A case in real cellular mobile radio (CMR) system together with the prediction results are also presented. As shown by...We study on the implementation flow of the radio computerized tomography (RCT) prediction method. A case in real cellular mobile radio (CMR) system together with the prediction results are also presented. As shown by the results, the RCT prediction method is marked for its convenience and rapidity, as well as its relative high precision even when the prediction procedure is highly simplified. Since it is developed according to the characteristics of wireless communication environments of our country and has concurrently merits from both statistical and deterministic prediction models, the RCT prediction method is in good agreement with engineering practices in cellular mobile communication in cities at home. Optimized by combining with other techniques, further improvement could be achieved in the stability and precision of the RCT prediction method which now serves as the core part of a software tool for commercial use in CMR system analysis and optimization.展开更多
Surveying the propagation path loss behavior of Shenzhen city and from the data recorded we can obtain the city’s path loss slopes, which can be comparatively regarded as the reliable bases of system design.
This poper presents a new method of estimating and correcting Doppler frequency shift in anM-ary (D)PSK receiver. The performance is discussed. Analytical and simulation results are presentedand the error probability ...This poper presents a new method of estimating and correcting Doppler frequency shift in anM-ary (D)PSK receiver. The performance is discussed. Analytical and simulation results are presentedand the error probability performance of the (D)PSK receiver is evaluated in the presence of the Doppler correction. It is shown from analytical and simulation results for constant Doppler shift that the methodperforms excellently.展开更多
TD-SCDMA has been decided as the standard for TDD mode of the 3rd Generation mobile radio system by International Telecommunications Union (ITU),it is a important breakthrough in a century communication history. A nov...TD-SCDMA has been decided as the standard for TDD mode of the 3rd Generation mobile radio system by International Telecommunications Union (ITU),it is a important breakthrough in a century communication history. A novel downlink multiuser transmission scheme Joint Transmission (JT) is proposed based on the reciprocity that in the case of TDD the same channel impulse responses are valid for both the uplink and the downlink, it can enhance system performance and reduce system complexity. Because no channel estimation is necessary at the MSs, the data detection effort is dramatically reduced. This paper apply JT in Time Division CDMA (TD-SCDMA) and analyze its proformance in contrast to state of the art TD-CDMA transceivers. The computer simulation results illustrate the superiority of the novel scheme in terms of the system performance in the downlink of TD-SCDMA.展开更多
This paper proposes an algorithm to design a cost optimized topology for thefixed part of a mobile network. For the given locations of base stations and mobile switchingcenters, the algorithm decides the number and po...This paper proposes an algorithm to design a cost optimized topology for thefixed part of a mobile network. For the given locations of base stations and mobile switchingcenters, the algorithm decides the number and position of the base station controllers as well asthe way the base stations are connected to the base stations controllers.展开更多
文摘Cognitive Radio Networks(CRNs)have become a successful platform in recent years for a diverse range of future systems,in particularly,industrial internet of things(IIoT)applications.In order to provide an efficient connection among IIoT devices,CRNs enhance spectrum utilization by using licensed spectrum.However,the routing protocol in these networks is considered one of the main problems due to node mobility and time-variant channel selection.Specifically,the channel selection for routing protocol is indispensable in CRNs to provide an adequate adaptation to the Primary User(PU)activity and create a robust routing path.This study aims to construct a robust routing path by minimizing PU interference and routing delay to maximize throughput within the IIoT domain.Thus,a generic routing framework from a cross-layer perspective is investigated that intends to share the information resources by exploiting a recently proposed method,namely,Channel Availability Probability.Moreover,a novel cross-layer-oriented routing protocol is proposed by using a time-variant channel estimation technique.This protocol combines lower layer(Physical layer and Data Link layer)sensing that is derived from the channel estimation model.Also,it periodically updates and stores the routing table for optimal route decision-making.Moreover,in order to achieve higher throughput and lower delay,a new routing metric is presented.To evaluate the performance of the proposed protocol,network simulations have been conducted and also compared to the widely used routing protocols,as a benchmark.The simulation results of different routing scenarios demonstrate that our proposed solution outperforms the existing protocols in terms of the standard network performance metrics involving packet delivery ratio(with an improved margin of around 5–20%approximately)under varying numbers of PUs and cognitive users in Mobile Cognitive Radio Networks(MCRNs).Moreover,the cross-layer routing protocol successfully achieves high routing performance in finding a robust route,selecting the high channel stability,and reducing the probability of PU interference for continued communication.
文摘In this paper, the bit error rate (BER) performance for typical mobile radio channels is simulated and analyzed based on a tapped delay line model. The investigation is focused on the propagation environments determined by the average delay profile and the Doppler spectra. The profile characteristics and their influences on channel behavior are also examined.
文摘That making phone calls had nothing to do with lightning strike was proved from the aspects of radio wave characteristics,receiving and transmitting frequency,power as well as the electromagnetic induction of mobile phones. And through assuming mobile phone could trigger lightning,the probable death toll disproved the absurdity of mobile phone triggered lightning. And we concluded that making phone calls in thundery days would not increase the probability of lightning stroke,and calls could be made in thundery days as long as in the safe position.
文摘A new method for the coverage prediction of Cellular Mobile Radio (CMR) system is developed and its basic principle is presented. Unlike the Statistical Prediction Model (SPM) that estimates propagation loss by empirical formulas or the Deterministic Prediction Model (DPM) that reckons propagation loss with analytical expressions, the Radio Computerized Tomography (RCT) method does not seek to express the propagation loss explicitly. The 2 D distribution of propagation loss factor is computed using CT technique, based on measured data collected through drive test under appropriate geometric constraint. The total propagation loss can be obtained by integral of propagation loss factor along the equivalent ray path. The advantages and limitations of the technique, as well as its implementation are discussed.
文摘We study on the implementation flow of the radio computerized tomography (RCT) prediction method. A case in real cellular mobile radio (CMR) system together with the prediction results are also presented. As shown by the results, the RCT prediction method is marked for its convenience and rapidity, as well as its relative high precision even when the prediction procedure is highly simplified. Since it is developed according to the characteristics of wireless communication environments of our country and has concurrently merits from both statistical and deterministic prediction models, the RCT prediction method is in good agreement with engineering practices in cellular mobile communication in cities at home. Optimized by combining with other techniques, further improvement could be achieved in the stability and precision of the RCT prediction method which now serves as the core part of a software tool for commercial use in CMR system analysis and optimization.
文摘Surveying the propagation path loss behavior of Shenzhen city and from the data recorded we can obtain the city’s path loss slopes, which can be comparatively regarded as the reliable bases of system design.
文摘This poper presents a new method of estimating and correcting Doppler frequency shift in anM-ary (D)PSK receiver. The performance is discussed. Analytical and simulation results are presentedand the error probability performance of the (D)PSK receiver is evaluated in the presence of the Doppler correction. It is shown from analytical and simulation results for constant Doppler shift that the methodperforms excellently.
文摘TD-SCDMA has been decided as the standard for TDD mode of the 3rd Generation mobile radio system by International Telecommunications Union (ITU),it is a important breakthrough in a century communication history. A novel downlink multiuser transmission scheme Joint Transmission (JT) is proposed based on the reciprocity that in the case of TDD the same channel impulse responses are valid for both the uplink and the downlink, it can enhance system performance and reduce system complexity. Because no channel estimation is necessary at the MSs, the data detection effort is dramatically reduced. This paper apply JT in Time Division CDMA (TD-SCDMA) and analyze its proformance in contrast to state of the art TD-CDMA transceivers. The computer simulation results illustrate the superiority of the novel scheme in terms of the system performance in the downlink of TD-SCDMA.
文摘This paper proposes an algorithm to design a cost optimized topology for thefixed part of a mobile network. For the given locations of base stations and mobile switchingcenters, the algorithm decides the number and position of the base station controllers as well asthe way the base stations are connected to the base stations controllers.
