地空協(xié)同傳輸理論與方法

關(guān)新平　陳彩蓮　化存卿　張有光　高強(qiáng)

摘要：本研究針對我國中長期科技發(fā)展規(guī)劃對大型飛機(jī)的重大戰(zhàn)略需求，研究飛行器在復(fù)雜條件下進(jìn)近可視導(dǎo)航所需的空地通信網(wǎng)絡(luò)基礎(chǔ)科學(xué)問題。根據(jù)飛行器在不同飛行階段的運(yùn)動特點(diǎn)及對通信的需求差異，本研究從兩個方面展開研究：巡航區(qū)飛行器的混合式地空蜂窩網(wǎng)絡(luò)；進(jìn)近飛行器可靠通信的機(jī)場終端區(qū)無線mesh網(wǎng)絡(luò)。重點(diǎn)研究了網(wǎng)絡(luò)的基本組成和實(shí)現(xiàn)機(jī)理，并進(jìn)行大規(guī)模的試驗(yàn)和驗(yàn)證；為可視導(dǎo)航技術(shù)創(chuàng)新提供基礎(chǔ)理論支持。 在混合式地空蜂窩網(wǎng)絡(luò)架構(gòu)中，空中飛行器組成自組織網(wǎng)絡(luò)，地面VHF基站與區(qū)域管制中心聯(lián)網(wǎng)，整合所有導(dǎo)航、管制及服務(wù)相關(guān)信息。飛行器可與地面VHF基站通信，獲取所有與安全飛行相關(guān)的信息，并及時(shí)向地面提供自身的飛行數(shù)據(jù)；飛行器之間可自由通信，保證周圍態(tài)勢信息的及時(shí)獲取，縮小安全間隔，減少基站通信負(fù)荷。為建立具有可擴(kuò)展、可重構(gòu)特性的空地協(xié)同傳輸體系，本研究圍繞該混合式地空蜂窩網(wǎng)絡(luò)架構(gòu)，本研究著重研究了網(wǎng)絡(luò)系統(tǒng)容量分析方法及異構(gòu)網(wǎng)絡(luò)下多域協(xié)同編碼技術(shù)，提出網(wǎng)絡(luò)系統(tǒng)容量分析方法。優(yōu)化空地?cái)?shù)據(jù)鏈網(wǎng)絡(luò)結(jié)構(gòu)，獲得較高傳輸可靠性和較強(qiáng)復(fù)用能力，提高系統(tǒng)容量。 另一方面，在全天候、高交通密度和各種復(fù)雜的機(jī)場建筑布局情況下，保證飛行器和地面車輛在機(jī)場的安全、有序及快速運(yùn)行是機(jī)場運(yùn)行的重要目標(biāo)，也是提高機(jī)場對飛行器架次的處理能力、效率及安全的先決條件。因此，本研究在機(jī)場表面建立的無線mesh網(wǎng)絡(luò)利用運(yùn)行在場面上的飛行器、車輛、地勤人員及場面設(shè)備等作為通信節(jié)點(diǎn)，并在跑道周邊布設(shè)傳感器節(jié)點(diǎn)等，旨在快速、準(zhǔn)確地傳輸塔臺對飛行器、車輛和地面人員的指揮調(diào)度信息。利于實(shí)現(xiàn)安全、高效、高速、有序的民航航站空側(cè)交通管理工作，在全天候條件下能夠?qū)秸窘煌ㄟM(jìn)行科學(xué)的管理。由于機(jī)場終端區(qū)存在各種復(fù)雜的機(jī)場建筑，使得機(jī)場表面無線通信受多徑效應(yīng)干擾嚴(yán)重，因此本研究采用協(xié)作通信技術(shù)，利用場面塔臺和目標(biāo)節(jié)點(diǎn)間的空閑節(jié)點(diǎn)進(jìn)行信號的中繼轉(zhuǎn)發(fā)，有效提高傳輸?shù)目煽啃?。同時(shí)，為滿足突發(fā)事件報(bào)告對傳輸實(shí)時(shí)性的要求，提出了基于虛擬Agent 的事件報(bào)告?zhèn)鬏敊C(jī)制，有效減小傳輸時(shí)延。

關(guān)鍵詞：空地?cái)?shù)據(jù)鏈系統(tǒng)；航空自組網(wǎng)；網(wǎng)絡(luò)容量；可擴(kuò)展性；異構(gòu)信息傳輸；協(xié)作通信

Abstract：In this project， we propose an Aeronautical Ad-hoc network （AANET） architecture based on several ？ight paths， whereby the aircrafts in the cruise stage can get the information from the ground with the aid of ground stations and aircrafts can communicate with each other through multi-hop relays for information sharing and critical situational awareness. To improve the scalability and reconfiguration capability of the air-ground communication system， we investigate the method of analyzing the network capacity and propose a multi-domain collaborative network coding technology for heterogeneous information transmission. Due to the special structure of AANET， existing results on conventional mobile ad hoc networks are not applicable for determining the capacity scaling law of this network model. We prove an upper bound on the per-node capacity and construct a simple transmission scheduling scheme to achieve the lower bound， in this way， the capacity of the AANET is derived. The reason for the construction of the Airport Surface Wireless Mesh networks comes from several aspects. Top of the list comes lack of flexibility in existing airport communications infrastructure and underground cabling is expensive to deploy. Particularly， most of the aging infrastructures are costly to maintain and vulnerable； also， existing cabling infrastructure are not always available at all airports； the integration of communication is limited， resulting the lack of network connectivity. Moreover， current NAS modernization and anticipated “NextGen” Air Traffic System increase demands for CNS information sharing stakeholders. Therefore， Airport Surface Wireless Mesh networks integrates data from existing airport infrastructures， such as ASDE-X sensors， runway incursion prevention system， weather and wake sensors， constructing an information pool that can be used for controllers， pilots， airlines， ramp， deicing as well as service and emergency dispatch， et al. As a consequence， wireless mobile airport surface communications can greatly benefits the reliability， secure integration of voice/video/data at all airport locations. And enables “SWIM” networked integration of data sources and users， allows flexible， expandable， affordable deployment at airports of all sizes， while at the same time reduces VHF spectrum congestion.

Keywords：air-ground data link system； aeronautical ad-hoc network； network capacity； scalability； heterogeneous information transmission； cooperative communication