深空通信新型射頻技術(shù)

胡赟鵬++沈彩耀++沈智翔++張德偉++屠振

摘 要：深空通信射頻技術(shù)是深空通信關(guān)鍵技術(shù)之一，該課題圍繞我國(guó)未來(lái)深空探測(cè)任務(wù)的需求，重點(diǎn)突破適應(yīng)深空通信需求的低噪聲溫度射頻前端設(shè)計(jì)與多天線組陣增強(qiáng)系統(tǒng)相關(guān)關(guān)鍵技術(shù)，實(shí)現(xiàn)深空探測(cè)數(shù)據(jù)回傳的高效可靠接收。課題設(shè)計(jì)完成低噪聲溫度射頻前端，X/Ka頻段等效噪聲溫度達(dá)到25 K/50 K以下。突破HEMT晶體管低溫建模關(guān)鍵技術(shù)，實(shí)現(xiàn)低溫器件參數(shù)的高精度提取。針對(duì)超導(dǎo)濾波器的關(guān)鍵工藝技術(shù)，以及超導(dǎo)濾波器運(yùn)用軟件精確設(shè)計(jì)展開研究。提出了支持現(xiàn)有天線以任意形態(tài)組陣的全新多天線信號(hào)增強(qiáng)處理結(jié)構(gòu)，同時(shí)設(shè)計(jì)研制了多天線信號(hào)合成樣機(jī)及試驗(yàn)驗(yàn)證系統(tǒng)。該結(jié)構(gòu)可充分利用現(xiàn)有的接收天線和接收機(jī)，適用于非均勻組陣下各種調(diào)制方式、不同調(diào)制參數(shù)信號(hào)的無(wú)數(shù)據(jù)輔助合成，實(shí)現(xiàn)了對(duì)信號(hào)的盲處理。區(qū)別于傳統(tǒng)的僅利用固定參考信號(hào)實(shí)現(xiàn)信號(hào)間的時(shí)延估計(jì)方法，提出了一種基于準(zhǔn)合成輸出信號(hào)作為參考時(shí)延對(duì)準(zhǔn)算法，提高參考信號(hào)的信噪比，時(shí)延估計(jì)性能在低信噪比條件下其估計(jì)性能改善更為明顯。提出并實(shí)現(xiàn)了一種不依賴于單路信號(hào)信噪比計(jì)算的多天線信號(hào)合成權(quán)值盲估計(jì)算法，該算法無(wú)需任何信號(hào)先驗(yàn)信息和定時(shí)同步，解決了信號(hào)最大比合并中權(quán)值估計(jì)的通用性問題。針對(duì)通信信號(hào)特點(diǎn)，研究了多天線信號(hào)多層次聯(lián)合處理結(jié)構(gòu)，同時(shí)實(shí)現(xiàn)了符號(hào)檢測(cè)與同步的聯(lián)合處理，以及各路信號(hào)間的聯(lián)合同步與聯(lián)合符號(hào)檢測(cè)。在多路極低信噪比條件下，與傳統(tǒng)合成結(jié)構(gòu)的相比能夠進(jìn)一步提升處理增益。課題所取得成果對(duì)拓展更遠(yuǎn)距離的深空探測(cè)，實(shí)現(xiàn)極低信噪比條件下，大容量回傳數(shù)據(jù)的可靠接收具有十分重要的意義。針對(duì)我國(guó)深空探測(cè)發(fā)展的需求，該課題通過關(guān)鍵技術(shù)突破與創(chuàng)新有效提升深空數(shù)據(jù)傳輸能力，為我國(guó)未來(lái)深空科學(xué)技術(shù)與工程實(shí)施提供有力支撐，推動(dòng)我國(guó)空間科學(xué)與應(yīng)用的原創(chuàng)性發(fā)展。

關(guān)鍵詞：深空通信 低噪聲溫度射頻前端 多天線信號(hào)合成

Abstract： Deep space communication radio frequency （RF） technology is one of the key technologies for deep space communication. Around the needs of the deep space exploration， this subject has made a significant breakthrough in key areas of low noise temperature RF front-end design as well as multiple antenna arraying techniques to meet the needs of high reliable and efficient data transmission in deep space communication. This project developed a low noise temperature RF front-end with X/Ka band equivalent noise temperature reached 25 K/50 K. It made breakthrough in the key technology of modeling HEMT transistor in low temperature， and also realized the high-precision extraction of low temperature parameters. Superconducting filter on the key technology and using software accurate designing are specially researched. Besides， this project proposed a new multiple-antenna signal enhancement processing structure， which supports the existing antenna array in arbitrary form， and designed multiple antennas combining prototype and test system. This structure is suitable for non-uniform group array under various signal modulation mode， different modulation parameters. This project proposed a new time delay alignment algorithm using quasi combined signal as the reference， which improve the signal-to-noise ratio（SNR） of the reference signal， thus improve the time delay estimation performance. This project proposed a new weights estimation method， which is independent on single channel signal SNR calculation and does not need any priori information and timing synchronization. For the characteristics of communication signals， this project studied multi-antenna multi-level joint processing structure， achieving joint symbol detection and synchronization， as well as multiple signals joint synchronization and symbol detection. The above cooperative processing structure can achieve parameters estimation from multiple antenna at the same time， which can further enhance the processing gain under low SNR conditions. The above achievements are significant to be expanded to greater distance deep space exploration， achieving high-capacity high reliable data reception under low SNR condition. This project can effectively improve the deep space data transmission ability， which provide strong support for future deep space science， technology and engineering implementation in China.

Key Words： Deep space communication； Low noise temperature RF front-end； Multiple-antenna signal combining

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