Frame Synchronization Algorithm Research Articles

Алгоритм адаптивной кадровой синхронизации в системах сверхширокополосной радиосвязи

This paper introduces adaptive frame synchronization algorithm in HRP mode of IEEE 802.15.4-2020 radiocommunication system under unintentional; interference signals transmitted in HRP-CoU mode. Proposed algorithm is based on nulls adding to synchronization sequences and packet error rate control. True detection probability is estimated by MATLAB model.

Improvement of College English Teaching Model under the Background of Information Technology

In order to improve the effect of college English teaching reform, this paper combines information technology to improve the college English teaching mode. According to the digital processing requirements of English teaching resources, in order to make the loop establishment circuit time of automatic gain control independent of the input signal, this paper uses a logarithmic amplifier to detect it. Moreover, this paper combines the SC algorithm and the SC algorithm based on the time-domain PN sequence to propose a new frame synchronization algorithm. The algorithm has precise frame synchronization points and reduces the usage of hardware resources. Finally, this paper constructs a college English teaching system based on information technology. The experimental research results show that the college English teaching system based on information technology proposed in this paper has a good teaching effect.

Design of a General Hardware in the Loop Underwater Communication Emulation System

Underwater acoustic communication plays an important role in underwater wireless sensor network. Different from terrestrial radio channel, modeling of underwater acoustic channel is very challenging due to its unique and dynamic characteristics. In order to verify the proposed acoustic communication algorithms, a general emulation platform which can reduce the verification cost has a wide application prospect. In this paper, we design a general hardware in the loop underwater communication emulation system based on the LabVIEW and MATLAB software and real acoustic transducer. In the emulation system, LabVIEW calls MATLAB script to achieve algorithm implementation, and then uses DAQmx to send and receive data through the acquisition card. The proposed system supports a variety of modulation and demodulation methods, such as multiple frequency-shift-keying(MFSK), multi-carrier frequency-shift-keying(MCFSK), orthogonal frequency division multiplexing(OFDM), etc. In addition, in order to detect frame efficiently, we propose a light-weight frame synchronous algorithm. To verify the function of the systems, lake test and sea test are conducted for different algorithms.

A General Embedded Underwater Acoustic Communication System Based on Advance STM32

Underwater acoustic communication (UAC) modem is an important infrastructure of underwater network construction. In recent years, with the performance improvement of the STM32 processor, the realization of reliable UAC through high-performance STM32 processor is conducive to reduce the system power consumption, cheapen the hardware cost, and ease the development difficulty. In this letter, we propose an embedded UAC system with the STM32H743 processor as the core and the peripheral sending/receiving circuit as the signal conditioning circuit module. The system can support a variety of modulation and demodulation methods, including single/multi-carrier frequency-shift keying and orthogonal frequency division multiplexing. Furthermore, in order to reduce the computational cost of the system, a fast and robust frame synchronization algorithm based on the segmented fast Fourier transform is applied. The sea trials show that the system can realize the reliable UAC transmission of 100 b/s-1 kb/s in the distance of 5-8 km in the shallow water area.

Training-aided joint frame and frequency synchronization for free space optical communication signals with low OSNR

In the photon-starving free space optical communication (FSOC) systems the optical signals received often exhibit a very low OSNR due to the large transmission loss. Thus the digital coherent combining (DCC) based digital coherent receivers (DCC-DCR) able to deal with FSOC signals with OSNR much lower than 0dB have attracted much attention in the FSOC field. As frame and frequency synchronization (FFS) algorithms are indispensable for DCC-DCRs, the FFS algorithms able to deal with FSOC signals with extremely low OSNR are of particular interest for the FSOC systems. In this paper we evaluate the performance of the existing FFS algorithms in the very low OSNR regime and propose a joint FFS algorithm with a larger noise tolerance, lower training sequence overhead and a wider frequency offset acquisition range. Numerical simulations are presented to illustrate the merits of the proposed FFS algorithm with respect to the existing algorithms.

Fast Frame Synchronization Design and FPGA Implementation in SF-BOTDA

To address the issues of high time consumption of frame synchronization involved in a scanning-free Brillouin optical time-domain analysis (SF-BOTDA) system, a fast frame synchronization algorithm based on incremental updating was proposed. In comparison to the standard frame synchronization algorithm, the proposed one significantly reduced the processing time required for the BOTDA system frame synchronization by about 98%. In addition, to further accelerate the real-time performance of frame synchronization, a field programmable gate array (FPGA) hardware implementation architecture based on parallel processing and pipelining mechanisms was also proposed. Compared with the software implementation, it further raised the processing speed by 13.41 times. The proposed approach could lay a foundation for the BOTDA system in the field with the associated high real-time requirements.

Analysis of Blind Frame Recognition and Synchronization Based on Sync Word Periodicity

Blind recognition of communication parameters has been studied for various applications including cognitive radios, non-cooperative communications, electronic warfare, etc. In this article, the identification of frame information, such as frame length and synchronization word (SW), and frame synchronization, is addressed over the wiretap channel, where no prior information of the frame structure is available, but only the existence of a repeated SW is known. Modifying the previous study, we propose two blind frame recognition and synchronization algorithms based on the correlation between two distinct windows of the received signal as well as the mean of periodic samples. The algorithms run in two steps. A multiple of frame length is estimated via the correlation and then other frame parameters are acquired using the mean of periodic samples with the estimate. Asymptotic analysis of the first algorithm shows that the error probability of estimation vanishes as the received data increases both in noiseless and noisy transmissions. The second algorithm improves the performance in the limited received data scenario. Simulation results as well as complexity analysis of the proposed algorithm are also shown.

A New Frame Synchronization Algorithm for Linear Periodic Channels With Memory

Identifying the start time of a sequence of symbols received at the receiver, commonly referred to as frame synchronization, is a critical task for achieving good performance in digital communications systems employing time-multiplexed transmission. In this work we focus on frame synchronization for linear channels with memory, in which the channel impulse response is periodic and the additive Gaussian noise is correlated and cyclostationary. Such channels appear in many communications scenarios, including narrowband power line communications and interference-limited wireless communications. We derive frame synchronization algorithms based on simplifications of the optimal likelihood-ratio test, assuming the channel impulse response is unknown at the receiver, which is applicable to many practical scenarios. The computational complexity of each of the derived algorithms is characterized, and a procedure for selecting nearly optimal synchronization sequences is proposed. The algorithms derived in this work achieve better performance than the noncoherent correlation detector, and, in fact, facilitate a controlled tradeoff between complexity and performance.

A Synchronization Algorithm for Burst-Mode MR-OFDM System of 802.15.4g

This paper presents a refined coarse frame synchronization algorithm for long repeated-sequence based preamble STF (short training field) in burst mode MR-OFDM system of 802.15.4g which is of low decision delay and resistant to timing uncertainty due to metric plateau. The precision of coarse timing and frequency offset estimation is improved. A fine symbol timing and frequency offset estimation algorithm based on LTF (long training field) is also proposed which provides an overall solution for the synchronization of burst mode MR-OFDM system. Simulation results are given to provide reference for implementation.

Cell search and synchronization in 5G NR

An overview of the physical signals foreseen by the 3GPP 5G New Radio specification for frame synchronization and cell search in fifth- generation wireless broadband access systems is presented in the paper. The frame synchronization algorithm and the cell initialization procedure are demonstrated. An estimate of probability of error detection of a physical identifier by the signals of the primary and secondary synchronization is obtained. The comparison of the successful synchronization in AWGN channel for 4G LTE and 5G NR is shown.

Exploring Physical Frame Format Design and Synchronization Algorithm for Optical Communication

Space optical communication has been a hot topic in modern communication system research, because it has many advantages, such as good secrecy, large information capacity, strong anti-interference ability, and so on. Pulse position modulation (PPM) is an excellent modulation method. In view of the low rate of information transmission by a space optical communication system, an improved "empty-empty-zero" physical frame format is designed to improve its transmission rate. In view of the actual space laser digital receiver, the frame synchronization algorithm is designed in this paper. Based on the physical frame format, this paper focuses on the design of frame synchronization algorithm. In order to deal with the change of noise and other parameters, an adaptive threshold setting is proposed. Considering the engineering implementation, a simplified correlation filtering implementation method is proposed. Finally, we designed the reception prototype system based on FPGA. The Matlab simulation, online simulation and experimental verification prove that the proposed method is correct and reliable.

Discrete FRFT-Based Frame and Frequency Synchronization for Coherent Optical Systems

A joint frame and carrier frequency synchronization algorithm for coherent optical systems, based on the digital computation of the fractional Fourier transform (FRFT), is proposed. The algorithm utilizes the characteristics of energy centralization of chirp signals in the FRFT domain, together with the time and phase shift properties of the FRFT. Chirp signals are used to construct a training sequence (TS), and fractional cross-correlation is employed to define a detection metric for the TS, from which a set of equations can be obtained. Estimates of both the timing offset and carrier frequency offset (CFO) are obtained by solving these equations. This TS is later employed in a phase-dependent decision-directed least-mean square algorithm for adaptive equalization. Simulation results of a 32-Gbaud coherent polarization division multiplexed Nyquist system show that the proposed scheme has a wide CFO estimation range and accurate synchronization performance even in poor optical signal-to-noise ratio conditions.

Frame-based synchronization adaptive method for systems based on DVB-S2 standard on FPGA

Introduction. With the development of digital technology, increasingly greater attention is paid to building radio-receiving paths based on SDR technology (Software Defined Radio). This technology involves the construction of SoC system on FPGA. Synchronization system is an important part of any radio system. This article analyzes the frame synchronization algorithms used today in terms of their efficiency and practical implementation on FPGA. Problem Statement. There are many frame synchronization algorithms for communication systems. Algorithms based on differential correlation method are extensively used these days because they are insensitive to phase and frequency distortions. The main disadvantage of the existing methods is their sensitivity to changes in the level of the input signal. Therefore, the development of the algorithm with an adaptive threshold for implementation on FPGA is an important task. Frame synchronization algorithm for DVB-S2 standard. This section shows analysis of modern frame synchronization algorithms, which are used in DVB-S2 receivers, and shows characteristics of MDP. Frame synchronization algorithm with adaptive threshold. Algorithm with adaptive threshold [P2], which is resistant to changes in the level of the input signal, is suggested. Also a comparative analysis of this method and methods listed above is made. Modification of the algorithm [P2] for implementation on FPGA. This section shows practical ways to implement the adaptive algorithm on FPGA hardware platform. In particular, the approximating method was used to find the location of the complex number modulus, the implementation of which is easily performed on the FPGA chip logic elements without loss of performance of the algorithm as a whole. Conclusions. Suggested adaptive frame synchronization algorithm eliminates Automatic Gain Control (AGC) system from signal processing phase. This approach of using an adaptive threshold can be used for more sophisticated algorithms, in particular for DPDI. In future works, these tasks will be addressed.

Performance, Complexity, and Receiver Design for Code-Aided Frame Synchronization in Multipath Channels

Next generation wireless communications systems are pushing the limits of both energy efficiency and spectral efficiency. This presents a challenge at the receiver when it comes to accomplishing tasks such as synchronization, channel estimation, and equalization and has motivated the development of code-aided iterative receiver algorithms in the technical literature. In this paper, we focus on the task of frame synchronization. While previous work has predominately assumed an additive white Gaussian noise channel, we develop code-aided frame synchronization algorithms for multipath channels. An iterative receiver is presented which integrates frame synchronization with iterative channel estimation, equalization, demodulation, and decoding. The receiver design includes a novel frame pre-processing stage to reduce the complexity of the proposed receiver. The complexity and performance of the proposed receiver is compared with that of a receiver based on conventional synchronization. The results demonstrate that the proposed receiver is capable of achieving a gain of up to 3 dB while increasing complexity by only 20%.

Frame Synchronization Algorithm for LDPC Coded Burst Systems

We present a frame synchronization algorithm for low-density parity-check (LDPC) coded burst transmissions, which combines a conventional pilots-assisted frame synchronization algorithm and a code-aided algorithm based on the mean magnitude of the soft outputs from the LDPC decoder. With moderate computational complexity, the proposed algorithm is more efficient in bandwidth than conventional pilots-assisted algorithms. When compared with other code-aided algorithms, the proposed algorithm offers a better trade-off between complexity and performance. Simulation results in the case of an 8-PSK system with (1944, 972) LDPC code show that the proposed algorithm can achieve a performance equivalent to that of the perfect frame synchronization, with a bandwidth efficiency loss of 0.06 dB due to the use of pilot symbols.

A frame synchronization algorithm for LDPC coded burst systems

A frame synchronization algorithm for LDPC coded burst systems

Frame and carrier frequency synchronization algorithm for wireless body area network

SummaryA wireless body area network (WBAN) is a radio‐frequency‐based wireless communication technology that consists of a number of different sensor and actuator nodes interconnected with a body gateway. Considering the constrained resources in WBAN devices, simple and noise‐robust synchronization algorithms are required. Frame synchronization and frequency offset estimation are extremely important in the design of a robust WBAN receiver. In this paper, a detection strategy such as frame synchronization and frequency estimation is described in the WBAN system, which can improve the receiver performance. In doing so, algorithms are designed or chosen for the frame detection, carrier frequency offset synchronization, and joint fine‐time and phase‐offset estimation by exploiting the spike‐like property of the physical layer convergence protocol preamble and the frame structure in the WBAN system. The performance of the WBAN synchronization receiver is verified by computer simulation. Copyright © 2015 John Wiley & Sons, Ltd.

Research and Realization of the HJ-1C Real-time Software Frame Synchronization Algorithm

Research and Realization of the HJ-1C Real-time Software Frame Synchronization Algorithm

Pseudo-noise preamble based joint frame and frequency synchronization algorithm in OFDM communication systems

Frame and frequency synchronization are essential for orthogonal frequency division multiplexing (OFDM) systems. The frame offset owing to incorrect start point position of the fast Fourier transform (FFT) window, and the carrier frequency offset (CFO) due to Doppler frequency shift or the frequency mismatch between the transmitter and receiver oscillators, can bring severe intersymbol interference (ISI) and inter-carrier interference (ICI) for the OFDM system. Relying on the relatively good correlation characteristic of the pseudo-noise (PN) sequence, a joint frame offset and normalized CFO estimation algorithm based on PN preamble in time domain is developed to realize the frame and frequency synchronization in the OFDM system. By comparison, the performances of the traditional algorithm and the improved algorithm are simulated under different conditions. The results indicate that the PN preamble based algorithm both in frame offset estimation and CFO estimation is more accurate, resource-saving and robust even under poor channel condition, such as low signal-to-noise ratio (SNR) and large normalized CFO.

Joint Blind Frame Synchronization and Encoder Identification for Low-Density Parity-Check Codes

In this paper, the problem involving joint blind frame synchronization and encoder identification for binary low-density parity-check (LDPC) codes of binary phase-shift keyed (BPSK) signals is tackled. The unknown encoder and time-delay can be blindly estimated simultaneously using the average log-likelihood ratios (LLRs) of syndrome a posteriori probability (APP). A new two-stage search method with a search step of size q by exploiting the quasi-cyclic nature of the parity-check matrix is devised to reduce the complexity of the blind frame synchronization algorithm. Numerous Monte Carlo simulations are evaluated to demonstrate the effectiveness of the new joint blind frame-synchronization and encoder-identification scheme for multi-path situations.