PERFORMANCE ANALYSIS OF REED-SOLOMON CODES IN DIGITAL COMMUNICATION SYSTEM USING LABVIEW

The Universal Software Radio Peripheral (USRP) from Ettus Research is a software defined radio (SDR) that has emerged as an affordable and capable radio used in both teaching and research applications. Despite its widespread use, precise specification of the transmit power of USRP SDR boards is not readily available in the manufacturer data sheets, and in this paper we present an experimental study of the transmit power for the B-series USRP SDR board from Ettus Research. Specifically, a USRP B200 SDR is used to setup extensive measurements of the output transmit power over its covered frequency range and the power variation with frequency along with its dependence on the transmit gain parameter in the USRP hardware driver (UHD) is evaluated. A discussion of the possible causes that lead to variations in the transmit power is also presented.

In this chapter, we describe different forward error correction (FEC) schemes currently in use or suitable for use in optical communication systems. We start with the description of standard block codes. The state-of-the-art in optical communication systems standardized by the ITU employ concatenated Bose–Chaudhuri–Hocquenghem (BCH)/RS codes [1, 2]. The RS(255,239), in particular, has been used in a broad range of long-haul communication systems [1, 2], and it is commonly considered as the first-generation of FEC [3, 4]. The elementary FEC schemes (BCH, RS, or convolutional codes) may be combined to design more powerful FEC schemes, e.g., RS(255,239) + RS(255,233). Several classes of concatenation codes are listed in ITU-T G975.1. Different concatenation schemes, such as the concatenation of two RS codes or the concatenation of RS and convolutional codes, are commonly considered as second generation of FEC [3, 4].

Forward error correction (FEC) is a key capability in modern satellite communications that provide the system designer with the needed flexibility to comply with the different applications' requirements. Reed-Solomon (RS) codes are well known for their ability to optimize between the system power, bandwidth, data rate, and the quality of service. This paper introduces an efficient decoding scheme for decoding the RS codes adhering to the Consultative Committee for Space Data Systems (CCSDS) standards based on Justesen's construction of concatenation. To maintain the standard output size, the proposed scheme first encodes every m - 1 bits using the single-parity-check (SPC) code, while the RS code encodes K SPC codewords into N symbols that are of the same size as CCSDS standard. Decoding on the inner SPC code is based on maximum-likelihood decoding Kaneko algorithm, while for the proposed coding scheme, the reduced test-pattern Chase algorithm is adapted for decoding the outer RS code. The simulation results show the coding gains of 1.4 and 7 dB compared with the algebraic decoding of RS codes over the AWGN and Rayleigh fading channels, respectively. Moreover, the adopted reduced test-pattern Chase algorithm for decoding the RS code achieves an overall complexity reduction of 40% compared with the conventional Chase decoding algorithm.

The universal software radio peripheral (USRP) is a versatile software defined radio (SDR) platform, developed by Ettus Research™, which is intended for a wide variety of applications ranging from communication links to RADAR. We have investigated another application of the USRP by implementing a transceiver capable of interrogating passive, wireless surface acoustic wave (SAW) sensors centered at 915MHz. Interrogation of wideband orthogonal frequency coded (OFC) SAW sensors imposes strict requirements on the timing and synchronization of the transceiver. In the standard mode of operation, samples are generated and streamed between the USRP and host computer, introducing latency and bandwidth limitations due to the sampling bus. To achieve the performance required for this application, the USRP FPGA has been modified to introduce new functionality. Extraction of the sensor temperature is accomplished with a custom matched filter correlator. The system is capable of interrogating multiple sensors and can quickly reconfigure the USRP. Demonstration of the USRP wireless sensor system is achieved by interrogating wireless SAW OFC sensors at 915MHz and extracting the sensor temperature.

• Core Innovation & Objective • Developed a novel, integrated system architecture combining a modified USRP X310 software-defined radio platform with a custom-designed high-power LED optical transceiver. • Achieved high-speed, low-latency, and highly reliable audio-video transmission over Visible Light Communication (VLC) for intelligent transportation and vehicle-to-vehicle (V2V) applications, particularly in electromagnetically sensitive environments. • Key Technical Breakthroughs • LED Bandwidth Extension: Designed an innovative active pre-equalization circuit (based on a 4th-order high-pass RC bypass and op-amps) that dramatically increased the 3dB modulation bandwidth of a commercial 15W LED from 3 MHz to 120 MHz. • High-Speed Modulation: Successfully implemented 64QAM-OFDM modulation/demodulation using GNU Radio on the USRP, enabling spectrally efficient data transmission. • Advanced Optical Design: Custom-designed optical lenses (transmitter and receiver) and a high-power Bias-T circuit for efficient AC/DC coupling, ensuring the LED operates in its linear region and maximizing optical power transfer. • Stable Link Performance: Incorporated an Automatic Gain Control (AGC) circuit at the receiver, stabilizing the output voltage between 1.2V - 2.0V and maintaining a modulation signal-to-noise ratio (SNR) > 23 dB over varying distances. • Outstanding System Performance • The experimentally demonstrated performance metrics are exceptional for a VLC system: • Peak Data Rate: 500 Mbps • Communication Distance: 0 - 110 meters • Bit Error Rate (BER): As low as 1.74 × 10⁻⁵ (far below the 1 × 10⁻⁴ target) • End-to-End Latency: < 0.1 s • Beam Angle: 11.5° (Transmitter) • Field of View (FOV): ≤ 18° (Receiver) • System Integration and Design • Hardware-Software Co-Design: Seamless integration of the USRP X310 (handling digital baseband processing) with the custom analog optical front-end. • Compact and Practical: The system is designed for external mounting on vehicles, offering a practical solution for real-world deployment. • Simulation-Guided Design: Used LightTools for optical design and Optisystem for communication link simulation to validate the design before implementation. • Significance and Application Value • Solves Critical Challenges: Provides a high-speed, secure, and EMI-free communication alternative to traditional RF in environments like military operations, petroleum facilities, and intelligent transportation systems. • 6G Potential: Serves as a practical reference for the development of VLC as a complementary technology in 6G networks. • Demonstrates Feasibility: Successfully proves the viability of using commercial LEDs and USRP platforms for building high-performance, medium-to-long-range optical communication systems. • This work represents a significant step forward in practical high-speed VLC system design, combining theoretical innovation with robust engineering to achieve state-of-the-art performance. Existing vehicular VLC systems suffer from limited bandwidth, short transmission distances, low data rates, and support only a narrow range of communication services. To address these issues, this paper proposes a vehicle-mounted high-speed LED visible light communication (VLC) system based on Universal Software Radio Peripheral (USRP). Leveraging 64QAM-OFDM digital modulation, an improved USRP X310 hardware platform, and a PC, we establish a novel architecture comprising digital baseband and optical transceiver modules. The baseband module eliminates traditional spectrum-shifting circuits and antennas, retaining only FPGA and ADC/DAC units. Audio/video files undergo 64QAM-OFDM modulation directly on the PC, with modulated signals output via DAC to a custom-designed wide-bandwidth LED transceiver. A broadband hardware equalization network based on a fourth-order RC bypass circuit was designed expands the 3dB bandwidth of high-power LEDs from 3 MHz to 120 MHz. Combined with automatic gain control (AGC), this achieves an optical transceiver with 12–15 W output power, >23 dB optical modulation signal-to-noise ratio (SNR), and stable receiver output voltage (1.2–2.0 V). The resulting compact system delivers low latency, high data rates, and high reliability. Under aligned optical path conditions, the system achieves >1 Mbit/s at 110 m (BER 0.49 × 10⁻⁵, delay 0.009-0.05s) and a peak rate of 500 Mbit/s at 10 m (BER 7.4 × 10⁻⁵), with an 11.5° transmit angle and a receiver field of view (FOV) of less than 18°. This work demonstrates the feasibility of high-power LED-based 64QAM-OFDM communication using USRP X310 for medium- to long-range vehicular links, providing a reference for intelligent transportation systems.

Digital Video Broadcasting-Terrestrial second generation (DVB-T2) systems are increasingly deployed for high quality terrestrial broadcasting. However, low Signal-to-Noise Ratio (SNR) conditions in urban and fringe coverage areas pose significant challenges, resulting in elevated Bit Error Rates (BER) and degraded service reliability. Forward Error Correction (FEC) techniques, particularly Low-Density Parity-Check (LDPC) and Bose Chaudhuri Hocquenghem (BCH) codes, play a crucial role in mitigating transmission errors and ensuring robust communication. This study investigates a systematic approach to optimizing LDPC and BCH FEC schemes to enhance transmission reliability and minimize BER under low-SNR conditions in DVB-T2 networks. Using simulation-based analyses, the study evaluates multiple LDPC code rates (e.g., 1/2, 2/3, 3/4) in combination with BCH codeword lengths and error-correcting capabilities. Results indicate that an optimized LDPC (64800, 32400) configuration combined with a BCH (255, 239) code significantly reduces BER, achieving approximately 10⁻⁵ at an SNR of 2 dB, compared to a BER of 10⁻³ using standard DVB-T2 FEC configurations. Additionally, iterative decoding algorithms for LDPC were fine-tuned to balance convergence speed and error correction performance, demonstrating a 25% reduction in decoding iterations without compromising reliability. The analysis also explores trade-offs between redundancy, throughput and latency, highlighting the practical considerations for real-world deployment. The findings underscore that strategic optimization of LDPC/BCH FEC parameters is critical for maintaining broadcast quality in low-SNR scenarios. By enhancing error resilience and reducing BER, the proposed approach improves signal integrity, supports consistent reception in fringe areas and maximizes spectrum efficiency. This work provides a foundation for adaptive FEC strategies in future DVB T2 systems, enabling broadcasters to deliver reliable high-definition content even under challenging channel conditions.

In the field of data-driven healthcare systems, wireless-based human activity monitoring in an indoor environment is getting popular. Localization of human activities can help patients to get remote healthcare. Wearable devices are employed in modern healthcare monitoring systems, despite the fact that they can be inconvenient and expensive. Several studies have shown that analyzing variations in Channel State Information (CSI) can be used to identify activities in an indoor environment and monitor health utilizing radio frequencies. The results of an experiment using Software Defined Radio (SDR) to identify and localize human activities while a human subject performed six different classes of activities (no-activity, leaning forward, sitting, standing, walking-Rx, walking-Tx). The CSI extracted from the communication channel between two Universal Software Radio Peripherals (USRP) devices communicating and operating as SDRs was used to collect a total of 2100 sample data. The Extra Tree (ET) classifier outperformed the prior benchmark approaches in localizing six activities across the 21 classes. The proposed ET classifier can identify if the room is occupied and a human subject’s walking directions in two separate zones, as well as localize six distinct activities inside the room with an accuracy of 91% and 100% respectively.

The performance of forward error correction (FEC) based on Reed-Solomon coding is analyzed experimentally for a burst-mode upstream channel within a passive optical network (PON) testbed. During this analysis, the upstream FEC performance is impaired by inducing correlated and localized errors within the burst through the injection of optical transients. These transients emulate the optical signal variation associated with the add-and-drop events of wavelength channels within a long-reach optical link based on a chain of erbium doped fiber amplifiers (EDFAs). The robustness of the FEC has been analyzed by measuring the post-FEC bit error rate (BER) as a function of the amplitude of the emulated transients and their delay with respect to the transmitted bursts. A margin of approximately 4dB is demonstrated for the transient amplitude before the FEC degradation. Furthermore, while the post-FEC BER is strongly degraded by the emulated transients, the pre-FEC BER stays below the FEC threshold, demonstrating the importance of measuring the post-FEC BER in order to correctly characterize the FEC performance in PON upstream channels affected by optical transients.

Modern software defined radio (SDR) technologies have enabled surface acoustic wave (SAW) sensor interrogation systems that are small, inexpensive, and fully integrated. The universal software radio peripheral (USRP) is available as a commercial-off-the-shelf (COTS) SDR that can be programmed to fit a wide variety of applications and needs. Recent work at the University of Central Florida has demonstrated the USRP B200 as a SAW sensor interrogator. This paper expands upon previous efforts by implementing a standalone interrogation platform which utilizes the USRP B200 and embedded microcomputer. Recent advances in embedded processing platforms have enabled full Linux environments to be run, enabling high performance computation in a compact package. One such embedded platform, the MinnowBoard MAX, has been employed to perform the complex matched filter correlator post processing techniques as well as handle programming and communication with the USRP. The unit is self contained and can be operated without a traditional Desktop or Laptop. Performance of the interrogator has also been improved by adding and external RF switch and amplifier. The system is demonstrated by interrogating orthogonal frequency coded (OFC) SAW sensors at 915MHz and extracting the sensor temperature.

Direction of Arrival (DOA) estimation is an important fundamental problem in wireless signal processing. The current research on DOA estimation is mainly carried out in the MATLAB software simulation environment, but there is a large difference between the pure software simulation and the actual results. In order to better study the practical application, this paper uses two Universal Software Radio Peripheral (USRP) as the hardware base, and combines the Simulink software platform to realize the ratio amplitude algorithm direction measurement. In the paper, the reasons and solutions for amplitude calibration as well as data synchronization in the system are firstly described, then the formula of the amplitude ratio algorithm is fitted by the measured data, and finally the DOA estimation system is implemented and tested by USRP and Simulink. The experimental results show that the system is capable of accomplishing the DOA estimation function, which provides a convenient and reliable experience for source angle estimation as well as signal processing researchers.

This paper presents a comprehensive analysis and implementation of various error correction coding methods, focusing on Reed-Solomon (RS) codes and Liberation codes in RAID6 systems. RS codes are emphasized for their robust error correction capabilities, making them ideal for high-reliability environments such as enterprise data centers and mission-critical systems, where the ability to correct multiple errors or data losses is crucial. In contrast, Liberation codes are noted for their superior encoding efficiency and lower computational complexity, making them well-suited for high-performance systems with stringent speed requirements. Through experimental comparisons, this study also evaluates Cauchy Reed-Solomon (CRS) codes, EVENODD codes, and Blaum-Roth (BR) codes, identifying the strengths and weaknesses of each method in various scenarios. The findings underscore the importance of selecting the appropriate coding technique based on system-specific requirements, as different use cases benefit from different error correction schemes in terms of performance and data reliability. Additionally, this research highlights the potential of these coding methods in broader distributed storage applications and discusses the trade-offs between them. Future research directions are suggested, particularly in optimizing existing codes and expanding their application in more complex and distributed storage environments.

We propose a low complexity synchronization method for the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) mobile communication systems. A low complexity detection window, synchronization state machine, and two-stage detection are used to lower the computational complexity. The positions of the detection window and received samples are recorded, and the position and length of the detection window are controlled by the state machine. The positions are compared to decide if the received sample is useful for synchronization signal detection. Such techniques avoid unnecessary computations especially when implementing a receiver on a software defined radio (SDR) platform with general-purpose processors. We analyze the computational complexity of the proposed method and evaluate its performance based on simulations and using a Universal Software Radio Peripheral (USRP)-based SDR platform. The evaluation shows that the proposed method provides reliable and real-time synchronization signals on the considered SDR platform.

In this paper, the deployment of a radio monitoring system using software-defined radio (SDR) technologies is addressed. The main advantage of using software-defined radio is its reconfigurable ability and flexibility to set the communication parameters when monitoring radio signals. We propose a feasible architecture of spectrum monitoring in which a control center is built using GNU Radio platform; some remote monitoring stations are built with SDR devices. At each remote station, an SDR dongle embedded with Realtek RTL2832U chip and a USRP (universal software radio peripheral) device are used to measure radio signals. Through TCP/IP network, measurement results or complex sampled data from the SDR devices can be sent to the monitoring center. Some key measurement tools for radio monitoring such as spectrum analyzer and audio/video player are also implemented in the proposed system. The major benefit of the proposed architecture is the cost-effective and flexible platform as compared with traditional spectrum monitoring systems. Moreover, both the radio signals and demodulated audio/video content can be remotely monitored at the control center.

The remarkable development of mobile networks has enabled ubiquitous communications that has transformed the way people connect with each other. Meanwhile, the growing adoption of smartphones, tablets, and increasingly bandwidth-intensive applications and services is driving unprecedented mobile broadband traffic growth; therefore, finding state-of-the-art strategies for improving the wireless transmission reliability has emerged significantly. In particular, to enable significant mitigation of the detrimental effects of multipath fading, high-performance forward error correction (FEC) techniques have now recognized to become a vital part of modern digital wireless systems. This work is dedicated to address a class of high-performance iteratively decoded FECs referred to as serial concatenation of quadratic interleaved codes (SCQICs) wherein the reordering arrays for permutor and unscramble in the FEC encoding/decoding entities enjoy the remarkable algorithm proposed by Takeshita et al. seminal contribution which: (1) yields provisioning coding gain in both waterfall and error-floor regions of the bit error rate (BER) performance curve (2) enables possibility of analysis and compact representation, (3) requires straightforward implementation. We have observed that their utilization for the modern wireless communications applications remained scarce due to the lack of strong and comprehensive performance predictions over the different statistical wireless channel models. Hence, in this paper, we endeavor to analyze and examine the error-correction capability of SCQICs vastly from the various aspects, and investigate their resultant coding gains in different wireless Doppler environments.

In this paper, we propose a real-time transmission and reception scheme for high-quality video using the directional antenna with the smart beamforming. We implemented a Software Defined Radio (SDR) testbed based on Universal Software Radio Peripheral (USRP) and LabVIEW, which can provide a cost effective solution for prototyping wireless communication systems. First, the major challenge for the streaming high quality video is high data rate. In our proposed system, the high data rate up to 56 Mbps is obtained with the directional beamforming transmission/reception. Second, packet efficiency, i.e., successful packet reception of the system should be high. In our proposed system, the packet efficiency up to 98.56% is achieved of by our developed algorithm. Third, the frame rate of the video transmission, which should be high, is attained at 30 fps in our implementation. The high power at the receiver is achieved by the use of the directional antenna. The experimental results show that the Inter Symbol Interference (ISI) is reduced to the great extent. Furthermore, the proposed solution is investigated by using high-order modulation techniques like 64-QAM and 256-QAM.