DVB-T2 Systems Research Articles

Low Complex Standard Conformable Transceiver based on Doppler Spread for DVB-T2 Systems

This paper addresses a novel Alamouti space-frequency block decoding scheme with discontinuous Doppler diversity (DDoD) and cyclic delay diversity (CDD). We investigate different antenna diversity concepts, which can be applied to orthogonal frequency division multiplexing (OFDM) systems over highly frequency selective channels. The main object of this research is standard compatibility and the effect of simple diversity techniques on the channel fading properties. Therefore, we analyze a receiver in terms of the effective channel transfer function, which leads to the possibility of optimizing diversity. Besides, a novel transceiver using DDoD is proposed, which increases the Doppler spread of the multipath fading channel without causing additional Intercarrier Interference (ICI). Moreover, an efficient Alamouti encoder and decoder based on CDD is proposed, which allows a high reliability and capacity enhancement. In order to evaluate the capability of that, we have implemented this scheme for the second-generation terrestrial video broadcasting (DVB-T2) system over different channels. Furthermore, mathematical analysis and simulation results show the bit error performance of the modified encoding method with these diversity techniques, performs mostly better than the other forms of encoding Alamouti over highly frequency-selective channels such as single frequency networks (SFN). The other advantages of the proposed method are simplicity, flexibility, and standard compatibility.

Measurement of digital video broadcasting-second generation terestrial (DVB-T2) signal in Kuala Lumpur, Malaysia

<span style="font-size: 9pt; font-family: 'Times New Roman', serif;">DVB-T2 (Digital Video Broadcasting – Second Generation Terrestrial) is one of the latest technical standards being developed by the DVB Project for DTT (Digital Terrestrial Television). It is also known as digital broadcasting trough terrestrial system since 2006 and is an extension of the DVB-T system as a second generation program to improve efficiency of the total system. It is important to perform a research on the performance of DVB-T2 because Malaysia has launched the free-to-air digital TV project since 2016 hence there is a need to know how well the signal is being received by viewers. This research focuses on a DVB-T2 transmission process which involve the transmission from Menara Kuala Lumpur transmitter to receivers located at 100 different locations. The performance of DVB-T2 can be determined by measuring the field strength, MER (Module Error Ratio) and BERaLDPC (Bit Error Rate after Low Density Parity Check decoder), and then a comparison between DVB-T and DVB-T2 systems can be made. Equipments involved in the measurement are indoor antenna, distribution amplifier, waveform monitor, field strength meter, DVB-T2 decoder and TV set as the receiver. Results are recorded in Microsoft Excel and analyzed using MATLAB software. The result of the measurement shows92% of the test points had higher reading than the baseline value which means better reception of digital TV signal is delivered to the location.Comparison between DVB-T and DVB-T2 performance shows that field strength of the DVB-T2 system is slightly higher by 1.5 % – 3.8 % from DVB-T</span><p class="MsoNormal"><span style="font-size: 16.0pt; line-height: 107%; mso-bidi-font-style: italic;">Measurement of digital video broadcasting-second generation terestrial (DVB-T2) signal in Kuala Lumpur, Malaysia</span></p>

An Optimal Low Complexity PAPR Reduction Technique for Next Generation OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is an efficient multi-carrier modulation technique that underlies most of the current and probably future high-speed wireless communication systems. However, the OFDM waveform is characterized by a high peak-to-average power ratio (PAPR), especially when a large number of subcarriers are used. A high PAPR is a major waveform defect since it leads to non-linear distortion when passing through the transmitter's power amplifier. Most of the PAPR reduction techniques found in the literature reduce the PAPR mainly at the cost of either excessive computational complexity or degrading the transmission bit error rate (BER). We propose a low-complexity technique for PAPR reduction based on linear scaling of a portion of signal coefficients by an optimal factor. This paper is backed up by the extensive analysis of various performance metrics, which leads to optimal choices of key parameters and hence maximum achievable gains. The analytic and simulated results show that the proposed technique is capable of reducing the PAPR effectively with negligible effect on BER in return for a slight reduction in data rate. For example, for 1024 subcarriers, the PAPR can be reduced from 13 dB to below 7.4 or 6.9 dB, in return for only 1% or 2% reduction in data rate, respectively. In addition, the achievable PAPR varies very slightly in response to increasing the number of subcarriers. This offers a highly competitive and flexible tradeoff compared with those provided by current techniques found in the literature. Therefore, this technique has a very good potential for practical application in current and future OFDM-based systems, especially those which employ a very large number of subcarriers, such as LTE, DVB-T2, and 5G systems.

An Efficient FPGA Design and Performance Testing of the ACE Algorithm for PAPR Reduction in DVB-T2 Systems

Active constellation extension (ACE) is one of the common algorithms for peak-to-average power ratio reduction in digital video broadcasting-second generation terrestrial (DVB-T2) systems. In this paper, we study the implementation of the ACE algorithm for DVB-T2 on field programmable gate array (FPGA) platforms. For this purpose, a general hardware architecture with two parallel channels is first proposed. The proposed architecture is based on 16-bit fixed-point representation which can achieve a tradeoff between numerical accuracy and hardware cost. Moreover, the pipelining design is adopted in some units and arithmetic components of the proposed architecture, with respect to enhancement of working frequency. Aiming at a specific DVB-T2 system, the proposed architecture is implemented in a low-cost FPGA platform. Implementation results indicate that the fixed-point FPGA design involves less hardware overhead, and can run at a clock of up to 120.6 MHz and achieves a maximum throughput of 513 Kb/s. Finally, the performances of the fixed-point FPGA design are verified on a laboratory prototype. Experimental results demonstrate that the proposed fixed-point FPGA design provides an accuracy performance that is very close to that of floating-point simulation counterpart.

A convergence broadcasting transmission of fixed 4K UHD and mobile HD services through a single terrestrial channel by employing FEF multiplexing technique in DVB-T2

Recently, a convergence broadcasting transmission for providing fixed 4K ultrahigh-definition (UHD) and mobile high-definition (HD) services through a single terrestrial channel is investigated by employing multiple-physical layer pipe (M-PLP) multiplexing and transmission technologies in digital video broadcasting (DVB)-second-generation terrestrial (T2) systems, and the scalable high-efficiency video coding (SHVC) technique. The M-PLP technique employs different code rates and constellation points for each layer of data and multiplexes differently encoded layers of data into a single frame, with no change of the inverse fast Fourier transform (IFFT) and cyclic prefix (CP). However, the IFFT size should be increased, and the CP size should be decreased for the 4K UHD layer while the opposite is true for the HD layer. Another aspect is that HD layer data are more important than 4K UHD layer data for reliable SHVC decoding, and thus the IFFT size should be decreased and the CP size should be increased for the HD layer to be robust to channel situations. In this paper, the possibility of a terrestrial fixed 4K UHD and mobile HD convergence broadcasting service through a single channel employing the future extension frame (FEF) multiplexing technique is examined. FEF multiplexing technology can be used to adjust the IFFT and CP size for each layer, whereas M-PLP multiplexing technology cannot. We described the convergence broadcasting service scenario and proposed a transmission system structure by employing FEF and transmission technologies in DVB-T2 systems. Available transmission parameters are extracted and the reception performance of the transmission parameters is examined using computer simulations. From the results, for the 6 and 8 MHz bandwidths, reliable reception of both fixed 4K UHD and mobile HD layer data can be achieved under a static and fast fading multipath channel.

HEVC over DVB-T2 기반 지상파 4K-UHDTV 방송을 위한 양시청 기준값 실험실 테스트 결과

본 연구에서는 HEVC로 인코딩된 스트림을 6MHz 대역폭 DVB-T2 시스템을 통해서 전송하는 우리나라 지상파 4K-UHD 실험방송 환경에서, 상용 수신기 3종에 대해서 양시청 최소 신호 대 잡음비(ToV C/N)와 양시청 수신기 최소 입력 전계 레벨(Sensitivity)을 실험실 테스트를 통해서 측정하였다. 26.37Mbps 전송률을 기준으로, ToV 평균 C/N=18.8dB 정도로 측정되었고, 수신기 Sensitivity는 최소 -84.2dBm에서 최대 -80.0dBm으로 측정되었다. 이로부터, 수신기 노이즈 바닥(Floor)은 평균 -100dBm 가량으로 계산되었다. In this study, HEVC over DVB-T2 systems with a bandwidth of 6 MHz is considered, particularly for the terrestrial 4K-UHDTV broadcasting service in the Republic of Korea. The threshold of visibility carrier-to-noise power ratio (ToV C/N) and the receiver minimum required input level (sensitivity) for satisfying the subjective picture failure (SPF) condition are measured in the laboratory. It is observed, for transmitting 26.37 Mbps data stream correctly, that ToV C/N is 18.8 dB on average, and the receiver sensitivity is varied from minimum -84.2 dBm to maximum -80.0 dBm. Based on the results, the receiver noise floor is calculated by -100 dBm on average.

Coexistence Between DVB-T/T2 and LTE Standards in Common Frequency Bands

In the last decade, fulfilling the growing users' expectations on the quality of provided multimedia services is one of the biggest challenges for different wireless communication systems. However, many times, different kinds of wireless systems can operate in the same (shared) frequency band. Such coexistence generally negatively affects the performance of the systems colliding. This is especially true for the widely used Digital Video Broadcasting-Terrestrial (DVB-T) or upcoming DVB-2nd Generation Terrestrial (DVB-T2) and Long-Term Evolution (LTE) standards, operating in Europe. Hence, the aim of this paper is to explore the impact of interfering mobile telecommunication services on the mobile TV services provided by LTE and DVB-T/T2 systems in the same frequency band. For the simulation of the coexistence between the LTE and DVB-T/T2 services on the physical layer level, an appropriate method is proposed and complex simulation tools are coupled. The results, presented as a dependence of modulation error ratio at the receiver input and bit error ratio at the channel decoder input on the spectral level ratio, show comparable performances for DVB-T and DVB-T2 systems. Results from simulations are verified by laboratory measurements and should help to better understand the influence of co-channel interferences from LTE mobile networks on DVB-T/T2 networks for mobile transmission scenarios.

Comparison of Terrestrial DTV Systems: ISDB-TB and DVB-T2 in 6 MHz

The present paper completely discusses the ISDB-TB and the DVB-T2 systems. There are demonstrated the differences and similarities since BTS data entrance to ISDB-TB as well T2-MI to DVB-T2, up to base band generation. Tests for both broadcast television systems have been performed using 6 MHz of bandwidth. The tests procedure in laboratory used TOV (Threshold of Visibility) criteria under different transmission's parameters to ISDB-TB and DVB-T2. It was analyzed the TV interferences as sensibility performance, C/N threshold, Impulsive Noise and Multipath.

FEF (Future Extension Frame) 다중화 기법을 이용한 지상파 단일 채널 고정 4K UHD & 이동 HD 융합방송 전송시스템 개발에 관한 연구

UHDTV (Ultra High Definition TV)와 같은 실감의 대용량 방송과 방송망과 통신망을 결합한 융합방송 (Convergence Broadcasting)에 대한 연구가 세계적으로 활발히 진행되고 있다. 최근 DVB (Digital Video Broadcasting) - T2 (2nd Generation Terrestrial) 방송 전송 시스템에 채용된 Multiple-PLP (Physical layer Pipe) 다중화 및 전송 기법들과 최근 표준이 완료된 SHVC (Scalable High efficiency Video Coding) 영상 압축 기술을 채용하여, 지상파 단일 채널을 통해 4K UHD & HD 모바일 방송을 전송하는 전송시스템 개발에 관한 연구가 수행되었다. 하지만 Multiple-PLP 다중화 기법은 서로 다른 계층의 데이터를 각각 다른 채널 부호율과 변조 성상도를 적용하여 하나의 프레임을 통해서 전송할 수 있는 반면, 프레임 내의 OFDM (Orthogonal Frequency Division Multiplexing) 심벌의 크기나 보호구간의 크기는 달리할 수가 없다. 이에 본 논문에서는 다른 계층의 데이터의 FFT & 보호구간의 크기를 달리하여 전송할 수 있는 FEF (Future Extension Frame) 다중화 기법을 이용한 지상파 고정 4K UHD & 이동 HD 융합 방송의 전송 가능성 및 성능을 검증해 보았다. 이를 위해 DVB-T2 지상파 방송 전송 시스템에 채용된 전송 기법들과 FEF 다중화 기법을 적용한 지상파 단일 채널 고정 4K UHD & 이동 HD 융합방송 전송시스템의 구조들을 제안하였다. 이후에는 예측 분석한 SHVC 압축 후의 데이터 전송 요구량을 바탕으로, 제안한 융합방송 전송 시스템을 통해 6 MHz & 8 MHz 대역폭에서 두 계층의 데이터를 전송할 수 있는 최적의 전송 파라메터를 도출하고, 이에 따른 TOV (Threshold of Visibility)를 찾기 위해 AWGN (Additive White Gaussian Noise), 정적 Brazil-D, 그리고 TU (Typical Urban)-6 채널 하에서 수신 성능을 검증해 보았다. 그리고 이를 통해 6MHz 및 8MHz 대역폭에서 4K UHD & HD 계층의 데이터를 고정 수신 그리고 수신 속도가 매우 빠른 이동 환경에서 원활히 수신할 수 있음을 보였다. In this paper, the possibility of a terrestrial fixed 4K UHD (Ultra High Definition) and mobile HD (High Definition) convergence broadcasting service through a single channel employing the FEF (Future Extension Frame) multiplexing technique in DVB (Digital Video Broadcasting)-T2 (Second Generation Terrestrial) systems is examined. The performance of such a service is also investigated. FEF multiplexing technology can be used to adjust the FFT (fast Fourier transform) and CP (cyclic prefix) size for each layer, whereas M-PLP (Multiple-Physical Layer Pipe) multiplexing technology in DVB-T2 systems cannot. The convergence broadcasting service scenario, which can provide fixed 4K UHD and mobile HD broadcasting through a single terrestrial channel, is described, and transmission requirements of the SHVC (Scalable High Efficiency Video Coding) technique are predicted. A convergence broadcasting transmission system structure is described by employing FEF and transmission technologies in DVB-T2 systems. Optimized transmission parameters are drawn to transmit 4K UHD and HD convergence broadcasting by employing a convergence broadcasting transmission structure, and the reception performance of the optimized transmission parameters under AWGN (additive white Gaussian noise), static Brazil-D, and time-varying TU (Typical Urban)-6 channels is examined using computer simulations to find the TOV (threshold of visibility). From the results, for the 6 and 8 MHz bandwidths, reliable reception of both fixed 4K UHD and mobile HD layer data can be achieved under a static fixed and very fast fading multipath channel.

A Low-Memory-Access Length-Adaptive Architecture for 2 $$^n$$ n -Point FFT

Fast Fourier transformation (FFT) is widely used in modern wireless communication and digital signal processing. Because memory access is a major cause of power dissipated by the long-length FFT architecture, this paper explores the design space expanded by FFT size and radix number in detail and presents a novel low-memory-access length-adaptive architecture for computing any long-length 2$$^n$$n-point FFT. The proposed hardware solution possesses the following three attractive features to reflect its novelty as compared to the existing designs. First, the authors identified that memory consumes major energy dissipation of a FFT processor and proposed to reduce memory access through decreasing the number of FFT butterfly stages. The second one is that we adopt the design concept of programmable processors to provide the flexibility in dynamically configuring the hardware for computing variable-length FFT without sacrificing the hardware utilization as contrary to the feed-forward architecture. Finally, a 16-bank memory organization is proposed to achieve conflict-free FFT operations for various radixes. Such low-memory-access length-adaptive architecture can reduce almost 70 % memory access or 30 % power consumption for FFT computation. After being implemented through 1P6M TSMC 0.18-$$\upmu $$μm CMOS technology, this work costs a core area of only 4.49 mm$$^{2}$$2 and meets the FFT real-time performance requirements of DVB-T2 systems when operated at 20 MHz frequency. The proposed design consumes only 1.44 nJ of energy per sample for computing FFTs. Through adopting the proposed low-memory-access algorithm, flexible length-adaptive architecture, and efficient 16-bank memory organization, 56 % power dissipation of the whole FFT chip can be saved.

Combined Time and Space Diversity: Mobile Reception in DVB-T and DVB-T2 Systems

The simultaneous delivery of fixed and mobile services in digital terrestrial TV (DTT) networks is a very attractive concept, as it allows the reuse of content, spectrum, and infrastructure. However, the provision of mobile services in terrestrial networks is challenged by the more severe propagation conditions of the mobile scenario. In this context, significant gains can be achieved by exploiting the diversity over time, frequency, and space.

A New Positioning System Using DVB-T2 Transmitter Signature Waveforms in Single Frequency Networks

A new positioning system using transmitter signature waveforms of DVB-T2 in Single Frequency Networks (SFNs) is proposed in this paper. Due to the wide coverage of the SFN and extremely high transmission power of digital television (DTV) transmitting stations, positioning based on DTV SFN can be considered as a promising complementary to remedy the poor coverage of the Global Positioning System (GPS) in dense multipath propagation environments. Based on the newly proposed transmitter signature waveform in DVB-T2 systems, transmitter identification and timing estimation using threshold-based first path detection method are jointly achieved, and subsequently utilized for Time-Difference-of-Arrival (TDOA)-based positioning approach. The proposed positioning system is fully compatible with the current DVB-T2 standard and therefore, no dedicated hardware modification is required. The performance of the proposed positioning system is evaluated through computer simulations under different signal propagation scenarios and compared with existing methods. Simulation results show that very high accuracy can be obtained with the proposed positioning system.

Cloud Transmission: A New Spectrum-Reuse Friendly Digital Terrestrial Broadcasting Transmission System

This paper introduces a new transmission system—“Cloud Transmission (Cloud Txn)” for terrestrial broadcasting or point-to-multipoint multimedia services. The system is based on the concept of increasing the reception robustness, and using the spectrum more efficiently. As such, the system is designed to be robust to co-channel interference, immune to multipath distortion, and is highly spectrum reuse friendly. It can increase the spectrum utilization significantly (3 to 4 times) by making all terrestrial RF channels in a city/market available for broadcast service. The system has the robustness required for providing mobile, pedestrian and indoor reception. It can be used for both small and large cell applications. The receiver is simple and energy efficient. The proposed system is scalable and can be implemented progressively, i.e., providing an easy transition from the traditional systems to the new Cloud Txn system. It can also coexist with the existing DTV systems and their newer versions, such as DVB-T2 or Super Hi-Vision systems.

Optimal Compensation of Dual Carrier Frequency Offsets for MISO-mode DVB-T2

Dual carrier frequency offsets (CFOs) occur in multiple-input single-output (MISO)-mode DVB-T2 systems, where signals are transmitted simultaneously from two distributed transmitters in a single frequency network (SFN). In this paper, we first derive an optimal compensation frequency for dual CFOs. We also propose an algorithm that optimizes the compensation frequency for the MISO-mode DVB-T2 application. Its performance is compared with the conventional scheme by using a full DVB-T2 simulator.