High-speed mobility and heavy-load traffic in mobile Ad hoc networks (MANET) may result in frequent topology changes and packet loss. To guarantee packet delivery, a novel stable backup routing (SBR) scheme is put forward in this paper, which consists of the establishment of backup routes and route maintenance. In SBR, backup routes are set up by overhearing MAC signals, and the bit error rate is considered in path selection for improving stability. To repair broken links effectively and reasonably, qualified backup routes are classified into three categories with different priorities, based on which the relevant nodes decide how to reconstruct the forwarding path. Extensive simulations demonstrate that our proposed method outperforms other comparable backup routing mechanisms in terms of packet delivery ratio, average delay and control overhead.

The security of highly resource constrained applications is often viewed in the literature from a single aspect of a specific cryptographic primitive. More precisely, most of the proposed lightweight cryptographic primitives focus on providing a single functionality within the available hardware area dedicated for security purposes. In this paper, we argue that for such applications, a cryptographic primitive that follows the cryptographic minimal design strategy maybe the only realistically adopted security solution where there is a constrained GE budget for all security functionalities. Following such a strategy, we propose the sLiSCP family of lightweight permutations employing two of the most hardware efficient and extensively cryptanalyzed constructions, namely a 4-subblock Type-2 Generalized Feistel-like Structure and round-reduced unkeyed Simeck. We claim that there exist no structural distinguishers for sLiSCP-b with a complexity below $2^{b/2}$ where b is the state size. We illustrate how the permutation provides (authenticated) encryption, hashing, and pseudorandom bit generation functionalities. Finally, we report two efficient parallel hardware implementations for the sLiSCP unified mode when using sLiSCP-192 (resp. sLiSCP-256) in CMOS 65nm ASIC with area of 2289 (resp. 3039) GEs and a throughput of 29.62 (resp. 44.44) kbps, and their areas in CMOS 130nm are 2498 (resp. 3319) GEs.

Multi‐source cooperative positioning systems relying on federated filtering have become attractive development directions of navigation strategy in real‐time localization and tracking under challenging urban environment. However, local Kalman filters of traditional federated filtering may result in divergence when the system model or the measurements is inaccurate, and the fixed information distribution coefficient in federated filter cannot adaptively reflect the performance of each local filter. To improve the precision and robustness of the integrated navigation system, a novel adaptive federated strong tracking Kalman filter with dynamic fading factor mechanism for multi‐sensor information fusion is proposed. Through iterative computation of the fading factor and updating the adaptive weight coefficients, strong tracking filter becomes robust to the uncertainty of system model. Meanwhile, an effective adaptive information distribution estimation algorithm based on the predicted residuals is constructed to balance the contributions of the kinematic model information and measurements on the state estimates. To ensure the stability of filtering, a simplified fusion strategy is established to solve the singular problem of the global covariance matrix of estimation error. Theoretical analysis and simulation results demonstrate the validity of the proposed approach in improving the accuracy and robustness of the integrated navigation and positioning systems. The proposed integrated multi‐modal cooperative navigation and positioning algorithm will be of great significance to the implementation of real‐time mobile target localization and tracking in harsh environment or dead zone.

Modern communication systems based on LDPC coded data transmission enable the operations at low signalto-noise ratio (SNR) conditions, close to the Shannon limit, where strict synchronization is required to ensure the optimal performance of the receiver. Residual offsets left by imprecise synchronization would lead to SNR degradation at the decoder, yet its elimination remains an issue at low SNRs. In this paper we focus on the accurate estimation of carrier frequency offset, and propose a novel frequency estimator with moderate computational complexity, which has wider, signal-length-independent estimation range and lower variance close to the Cramer–Rao bound (CRB), compared to other existing methods. Based on the proposed estimator, we establish a new structure of iterative synchronization embedded decoder by utilizing the expectationmaximization (EM) algorithm. The presented decoder exhibits a capability to significantly alleviate the performance degradation caused by residual offsets and to achieve performance enhancement for both the decoder and synchronizer. Furthermore, we develop a general frequency estimation framework for joint acquisition and fine carrier synchronization, which shows superior performance of low error metric. The proposed frequency estimator and improved frameworks will be of great significance to the implementation of the signal reception in high dynamic wireless communication systems at low SNR conditions.

Authenticated Encryption with Associated-Data (AEAD) can ensure both confidentiality and integrity of information in encrypted communication. Distinctive variants are customized from AEAD to satisfy various requirements. In this paper, we take a 128-bit lightweight AEAD stream cipher Fountain as an example. We provide a general cryptographic solution with three Fountain variants. These three variants are for encryption, message authentication code (MAC) generation, and authenticated encryption with associated data, respectively. Besides, we propose area-saved and throughput-improved strategies for the FPGA implementation of Fountain. The conventional paralleled hardware implementation leads to much resource-consuming with higher parallel width. We propose a hybrid architecture with parallel and serial update modes simultaneously. We also analyze the trade-off between area occupation and authentication latency for those two architectures. According to our discussion, hybrid architectures can perform efficiently with higher throughput than most ciphers, including Grain-128 x32. Our Fountain keystream generator occupies 46 slices on Spartan-3 FPGAs, smaller than most ciphers with the same security level, and even smaller than the 80-bit security level cipher Trivium. In summary, the customized Fountain with optimized implementations on FPGA is suitable for various applications in the field of IoT.