| 摘要: | 物聯網的發展將給人類帶來深刻的變革， 同時 物聯網被視為現在及未來無線通信技
術的一股重要驅動力量 它可以實現人與物、物與物之間的全面連接，為人類帶來更加
便捷、高效、安全的生活和工作方式。
窄頻物聯網 Narrowband Internet of Things NB IoT 是大規模機器型通信中的一
項強大技術，在即將到來的 新世代 無線通信中至關重要。 第 三代合作夥伴計劃 3GPP 中
的 NB IoT 標準 承諾在對延 遲寬容的應用中 為大量低吞吐、低成本 的 設備提供更佳 的覆
蓋範圍， 並且 還 具有較低的功耗 。 同時 NB IoT 廣泛地使用了 長期演進 (Long Term
Evolution, LTE 的設計，包括下行正交分頻多址接入、上行單載波分頻多址接入、通道
編碼、速率匹配 等 。然而，一種新型窄頻實體 隨機存取通道 已被重新設計為具有單音頻
率跳躍的前導 信號。 而 本文研究了 NB IoT 物理隨機存取 通道的隨機接入前導設計和檢
測， 我們 稱為 NPRACH Narrowband Physical Random Access Channels 。
在本論文中， 描述了 3GPP NB IoT 系統中的 NPRACH 的系統架構和運作原理， 首
先使用 Neyman Pearson 準則設計了一個最佳的活動檢測方案，而 為了減少由不同載波
頻率偏移 (C arrier Frequency Offsets, CFOs) 所帶來的頻率偏移，本文 使用了 一 種 聯合最大
概似估計 Joint Maximum Likelihood Estimation JMLE 用於聯合估計 正規化載波頻
率偏移 Normalized Carrier Frequency Offset, NCFO 和時序誤差 Timing Error, TE 避免
了 時變頻率選擇性衰落通道所疊加的問題。 所以本文 在 接收端 採用 了一種 符元級匹配濾
波器 (Symbol level Matched Filter, SLMF) 以有效降低帶外雜訊和干擾，而不會過度累積
互相關中發生的相位增量。 並將 接收機算法 結果 進行模擬和分析，針對錯誤偵測的改良，
並根據模擬結果顯示，接收機確實能 有效地降 低誤報和遺漏概率 ，改善系統的性能與效
率。;The development of the Internet of Things (IoT) will bring profound changes to humanity.
IoT is considered a significant driving force behind current and future wireless communication
technologies. It enables comprehensive connectivity between people and things, as well as
between things th emselves, providing a more convenient, efficient, and secure way of life and
work.
Narrowband Internet of Things (NB IoT) is a powerful technology in large scale machine
type communication and plays a crucial role in the upcoming generation of wireless
communication. The NB IoT standard, developed by the Third Generation Partnership Project
(3GPP), promises improved coverage for a large number of low throughput and low cost
devices in delay tolerant applications, while also offering lower power consumpti on. NB IoT
extensively utilizes design elements from Long Term Evolution (LTE), including downlink
orthogonal frequency division multiple access, uplink single carrier frequency division multiple
access, channel coding, and rate matching. However, a novel narrowband physical random
access channel has been redesigned with a single tone frequency hopping preamble. This paper
focuses on the design and detection of the random access preamble for the NB IoT physical
random access channel, which we refer to as Na rrowband Physical Random Access Channels
(
In this paper, we describe the system architecture and operation principles of NPRACH in
the 3GPP NB IoT system. We first design an optimal activity detection scheme using the
Neyman Pearson criterion. To mitigate the frequency offsets introduced by different carrier
frequency offsets (CFOs), we employ a Joint Maximum Likelihood Estimation (JMLE) to
jointly estimate the Normalized Carrier Frequency Offset (NCFO) and Timing Error (TE),
thereby avoiding th e superposition of time varying frequency selective fading channels. We
also utilize a symbol level matched filter (SLMF) at the receiver to effectively reduce out of
iii
band noise and interference without excessive accumulation of phase increments in cross
band noise and interference without excessive accumulation of phase increments in cross--ccorrelations. The receiver algorithm′s results are simulated and analyzed, focusing on the orrelations. The receiver algorithm′s results are simulated and analyzed, focusing on the improvement of error detection. The simulation results demonstrate that the receiver can improvement of error detection. The simulation results demonstrate that the receiver can effectively reduce the probabilities of false alarm and miss detection, thereeffectively reduce the probabilities of false alarm and miss detection, thereby improving system by improving system performance and efficiency.performance and efficiency. |
