In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and m...In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and multiple user detection techniques,our scheme can reach a high throughput of 0.98 without feedback under finite frame size settings,where the upper bound on performance is 1.Moreover,a lower bound on throughput performance is derived,which is tight in some parameter settings and can be used to approximate theoretical performance.Simulation results validate our analysis and confirm the advantages of our proposed scheme.展开更多
A new acknowledgment-type slotted-ALOHA code division multiple access （ACK-ALOHA-CDMA） channel which can be used in the inbound channels of very small aperture terminal（VSAT） networks is proposed in order to simpl...A new acknowledgment-type slotted-ALOHA code division multiple access （ACK-ALOHA-CDMA） channel which can be used in the inbound channels of very small aperture terminal（VSAT） networks is proposed in order to simplify the synchronization equipment of networks in the slotted-ALOHA- CDMA systems. By dividing all VSAT stations into M subsystems and sending out periodic inquiry signals from the Hub station to the VSAT station, the channel model is established. By the means of deriving multi-access interference（MAI） and packet detecting probability, steady-state throughput is calculated. By applying diffusion process theory to the analysis of the stability of the ACK-ALOHA-CDMA channel, the drift parameter a（r）, the diffusion parameter b（r） and the steady transition probability density p （r） are investigated. Simulation results indicate that significant performance improvement and high-bandwidth efficiency can be gained and one or two steady equilibrium points can be obtained by using this channel. Consequently, the ACK- ALOHA-CDMA channel is very suitable for cutting down on the expense of satellite VSAT systems and distributed packet radio networks.展开更多
文摘In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and multiple user detection techniques,our scheme can reach a high throughput of 0.98 without feedback under finite frame size settings,where the upper bound on performance is 1.Moreover,a lower bound on throughput performance is derived,which is tight in some parameter settings and can be used to approximate theoretical performance.Simulation results validate our analysis and confirm the advantages of our proposed scheme.
基金The Key Laboratory Foundation of Geographical Information Science of Jiangsu Province (No.JK20050304)the Key Laboratory Foundation of Virtual Geographical Environments of Ministry of Education(No.NS206005)
文摘A new acknowledgment-type slotted-ALOHA code division multiple access （ACK-ALOHA-CDMA） channel which can be used in the inbound channels of very small aperture terminal（VSAT） networks is proposed in order to simplify the synchronization equipment of networks in the slotted-ALOHA- CDMA systems. By dividing all VSAT stations into M subsystems and sending out periodic inquiry signals from the Hub station to the VSAT station, the channel model is established. By the means of deriving multi-access interference（MAI） and packet detecting probability, steady-state throughput is calculated. By applying diffusion process theory to the analysis of the stability of the ACK-ALOHA-CDMA channel, the drift parameter a（r）, the diffusion parameter b（r） and the steady transition probability density p （r） are investigated. Simulation results indicate that significant performance improvement and high-bandwidth efficiency can be gained and one or two steady equilibrium points can be obtained by using this channel. Consequently, the ACK- ALOHA-CDMA channel is very suitable for cutting down on the expense of satellite VSAT systems and distributed packet radio networks.
