本文選題：射頻識別 + 防碰撞算法��； 參考：《復(fù)旦大學(xué)》2014年碩士論文

【摘要】：射頻識別(RFID)技術(shù)是一種基于射頻通信的非接觸式的自動識別技術(shù),利用射頻信號作為載體傳遞信息和能量,實現(xiàn)與被檢測物體之間的信息交互。由于RFID技術(shù)具有通信距離遠(yuǎn),識別速度快,安全性好等特點,在供應(yīng)鏈管理、零售、身份驗證、防偽認(rèn)證、智能安防等領(lǐng)域有廣泛應(yīng)用。物聯(lián)網(wǎng)相關(guān)應(yīng)用的快速發(fā)展對RFID技術(shù)的識別速度提出了更高的要求。在很多應(yīng)用場合,當(dāng)讀寫器識別范圍內(nèi)的多個標(biāo)簽同時返回信號時,讀寫器無法識別到其中的任何一個標(biāo)簽,這時就會發(fā)生多標(biāo)簽碰撞。多標(biāo)簽防碰撞算法用于解決這種問題。目前廣泛采用的動態(tài)幀時隙Aloha算法將碰撞時隙(兩個或者更多標(biāo)簽同時響應(yīng)的時隙)當(dāng)成無效時隙�？梢宰C明,即使在最優(yōu)幀長的條件下,系統(tǒng)吞吐率存在理論極限,對算法的優(yōu)化只能使系統(tǒng)吞吐率無限接近理論極限。通過硬件輔助的方法將碰撞時隙轉(zhuǎn)化為成功時隙是一種提高防碰撞算法性能的可行的方案。本文對現(xiàn)有的多標(biāo)簽防碰撞算法進行了研究,分析了碰撞信號恢復(fù)的方法,提出了基于碰撞恢復(fù)的多種防碰撞算法優(yōu)化方法,包括碰撞信號恢復(fù)、標(biāo)簽個數(shù)檢測、幀長優(yōu)化等；建立了基于MATLAB的仿真平臺并對影響算法性能的因素做了分析與討論；提出了基于碰撞信號恢復(fù)的防碰撞算法硬件實現(xiàn)的系統(tǒng)架構(gòu),并對碰撞恢復(fù)電路做了硬件實現(xiàn)。上述方法可以有效地提高系統(tǒng)多標(biāo)簽識別的吞吐率并突破理論極限。仿真結(jié)果表明,采用本文設(shè)計的碰撞信號恢復(fù)算法,在信噪比為30dB的條件下,當(dāng)時隙內(nèi)存在兩個標(biāo)簽時,識別到兩個標(biāo)簽的概率為51%,識別到一個標(biāo)簽的概率為44%。識別1000個標(biāo)簽時,系統(tǒng)吞吐率可以由0.37提高至0.69。采用本文提出的幀長優(yōu)化算法,將衰減因子設(shè)為0.5,可以使系統(tǒng)吞吐率進一步提高至0.85。采用本文設(shè)計的標(biāo)簽個數(shù)檢測方法,可以檢測時隙內(nèi)存在的標(biāo)簽個數(shù),為碰撞信號恢復(fù)提供依據(jù),其檢測的平均準(zhǔn)確率可以達(dá)到90%。本文對碰撞信號模塊做了硬件實現(xiàn),在SMIC 0.13μm工藝的條件下,其面積為0.17mm2,相比于一個不包含碰撞恢復(fù)的數(shù)字系統(tǒng)面積增加了10%。
[Abstract]:Radio frequency identification (RFID) technology is a non-contact automatic identification technology based on radio frequency communication. Radio frequency signal is used as carrier to transfer information and energy to realize the information interaction with the detected object. Because of its long communication distance, high recognition speed and good security, RFID technology has been widely used in supply chain management, retail, authentication, authentication, intelligent security and other fields. The rapid development of Internet of things (IoT) applications requires higher recognition speed of RFID technology. In many applications, when multiple tags in the range of reader recognition return signals at the same time, the reader can not recognize any of the tags, so there will be multiple tag collisions. Multi-label anti-collision algorithm is used to solve this problem. The dynamic frame slot Aloha algorithm, which is widely used at present, regards the collision slot (the time slot that two or more tags respond at the same time) as invalid slot. It can be proved that even under the optimal frame length condition, the system throughput has a theoretical limit, and the optimization of the algorithm can only make the system throughput infinitely close to the theoretical limit. It is a feasible scheme to improve the performance of anti-collision algorithm by converting collision time slot into successful time slot by hardware aided method. In this paper, the existing multi-label anti-collision algorithms are studied, the methods of collision signal recovery are analyzed, and several anti-collision algorithms based on collision recovery are proposed, including collision signal recovery, tag number detection, frame length optimization and so on. The simulation platform based on MATLAB is established, and the factors affecting the performance of the algorithm are analyzed and discussed, and the hardware architecture of anti-collision algorithm based on collision signal recovery is proposed, and the hardware implementation of collision recovery circuit is also given. The above method can effectively improve the throughput and break the theoretical limit of multi-label recognition. The simulation results show that when the SNR is 30dB, when there are two tags in the gap, the probability of identifying two tags is 51 and the probability of identifying one tag is 44. The system throughput can be increased from 0. 37 to 0. 69 when 1000 tags are identified. Using the frame length optimization algorithm proposed in this paper, the attenuation factor is set to 0.5, and the throughput of the system can be further increased to 0.85. By using the method designed in this paper, the number of tags in the time slot can be detected, which can provide the basis for the recovery of collision signal. The average accuracy of the detection can reach 90%. The hardware implementation of the collision signal module is presented in this paper. Under the condition of SMIC 0.13 渭 m process, the area of the collision signal module is 0.17mm ~ 2, which is 10 times larger than that of a digital system without collision recovery.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TP391.44

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本文編號：1789844