Wideband receiver for Digital Radio Mondiale

Broadcasting within the traditional AM bands is set to change with the introduction of digital broadcasts. Wideband receiver architectures allow many of the advanced functions of standards such as Digital Radio Mondiale to be implemented and upgraded without changing the hardware. This article describes some of the design issues of wideband receivers and the performance of a practical receiver     

DRM在实验机上的应用

本文介绍PDM全固态中波广播发射机改造成DRM数字广播发射实验的原理,模拟和数字发射原理比较和分析,及应用在实验机的外场收测效果.同时也介绍了简单的接收方法.     

DRM传输系统服务质量的研究

数字调幅广播（DRM）是先进的数字广播系统,30MHz以下中短波信号通过地波或天波传播,无线环境变化大,文章提出一种实用的DRM服务质量监控系统来保证在服务区内良好的信号覆盖质量。     

An Improved Sampling Frequency Offset Estimator for OFDM-Based Digital Radio Mondiale Systems

After coarse synchronization in orthogonal frequency division multiplexing (OFDM) systems, there might still be a residual frequency offset (RFO) and a sampling clock frequency offset (SFO), which seriously degrade the performance of the systems. This paper suggests a simple way of estimating the SFO in OFDM-based digital radio mondiale (DRM) system. To demonstrate the efficiency of the proposed SFO estimator, comparisons are made with other existing estimators in terms of mean square error (MSE) performance, estimation range, and complexity.     

Estimation of Inchannel-Interference to Digital Radio Mondiale (DRM) Signals During Operation

This paper presents two novel interference measurement estimators for the DRM (Digital Radio Mondiale) system. They are based on the PSD (Power Spectral Density) estimation of the received spectrum, and provide interference estimation whilst the DRM transmitter is in operation. The first estimator provides successful detection of in-channel narrowband interference. If the interferer is an AM co-channel signal, the second estimator takes advantage of the specific characteristics of the DRM modulation to provide accurate measurement of the signal-to-interference ratio value. This allows protection ratio calculus and failure detection caused by interference.     

Digital Radio Mondiale (DRM) digital sound broadcasting in the AM bands

The paper describes the new world-wide broadcasting system Digital Radio Mondiale/spl trade/ (DRM/spl trade/) for the long, medium and short wave bands. It is originated by the goal of the consortium members to develop a flexible and efficient audio and data broadcasting standard. Better sound quality, more reliable reception in combination with additional service information make DRM a promising successor to analogue AM. Achieving good audio quality becomes a challenging task due to the limited bandwidth of 9 or 10 kHz, especially in often strongly impaired channels. Many other requirements, which were the basis for the system development, are illustrated. The article gives an overview of the system architecture, including the components for multiplexing, modulation, channel coding and source coding. Important receiver aspects, such as synchronization and channel estimation, are also described.     

PERFORMANCE EVALUATION OF LOW DENSITY PARITY CHECK CODES FOR DIGITAL RADIO MONDIALE （DRM） SYSTEM

In Digital Radio Mondiale （DRM） system, achieving good audio quality becomes a challenge due to its limited band-width of 9 or 10kHz and the very bad lading channels. Therefore, DRM needs highly efficient channel coding schemes. This paper, proposes the schemes which use the Low-Density Parity-Check （LDPC） coded Bit-Interleaved Coded Modulation （BICM） schemes for the implementation of DRM systems. Simulation results show that the proposed system is more efficient than the Rate Compatible Punctured Convolutional （RCPC） coded DRM system on various broadcast channels, and may be recommended as a coding technology for Digital Amplitude Modulation Broadcasting （DAMB） systems of China.     

Medium Wave Digital Radio Mondiale (DRM) Field Strength Time Variation in Different Reception Environments

This paper examines the temporal variability in fixed reception of the ground-wave propagated DRM (Digital Radio Mondiale) signal. This field strength analysis in the medium wave band has been performed using the first Spanish DRM field trial. Several fixed reception points located along radial routes provided the field strength sample distributions in rural and suburban areas. Additionally a second measurement campaign was carried out in several dense and open areas of downtown Madrid. The maximum likelihood estimations and logarithmic functions were used to analyse the fit of the experimental data with theoretical statistical distributions. A deep analysis of the most important parameters of the distribution has been carried out in order to characterize the field strength behavior in the different reception situations. It has been taken into account the influence of environment, measurement time interval, distance to the transmitter and the presence of critical reception impairments. The most remarkable result of this study has shown that the time variability of the ground-wave medium wave DRM channel is well approximated by a Log Normal and also by a Nakagami process. The Log Normal distribution is preferred as it is the one considered by the analog medium wave broadcasts for the ground-wave propagation case     

MSE Analysis of Sampling Frequency Offset Estimation Scheme for OFDM-Based Digital Radio Mondiale (DRM) Systems

A precise estimation and compensation of sampling frequency offset (SFO) is an important issue in an orthogonal frequency division multiplexing (OFDM) system because of its time-variant behavior. This paper considers the problem of SFO estimation for OFDM-based digital radio mondiale (DRM) systems. In this study, we develop expressions for the mean square error (MSE) of the conventional SFO estimators used in the OFDM-based DRM system. Their low-complexity variants and computation complexity are reported. The theoretical MSE analysis for different algorithms are validated by Monte-Carlo simulations within the framework of the OFDM parameter and pilot pattern defined in the DRM specification. It is also shown that the computation complexity of the low-complexity variants is significantly reduced, compared with that of original versions.     

Native intelligence for 6G mobile network: technical challenges,architecture and key features

The application of the artificial intelligence(AI) technology in the 5 th generation mobile communication system(5 G) networks promotes the development of the mobile communication network and its application in vertical industries, however, the application models of “patching” and “plug-in” have hindered the effect of AI applications. Meanwhile, the application of AI in all walks of life puts forward requirements for new capabilities of the future network, such as distributed training, real-time...     

电台数字直播间数字化改造及应用

从空间布局、灯光、音频、视频等几个方面,对广播电台直播间数字化改造及应用分别作了阐述.介绍了数字直播台和直播间音频通道,详细阐述了输入通道配置和“N-1”功能实现,并就网络直播的同步延时和视频信号的格式、码流及分辨率的设置作了说明.     

日本数字无线电广播

1 前言 数字无线电(Digital Radio)广播与现有的中波、 短波的调幅和超短波(甚高频VHF)的调频方式不 同,其声音信号是采用数字信号如脉码调制(PCM)进 行广播的方式。 数字无线电广播,在欧洲常称作数字音频广播     

数字化渔用电台设计

本文介绍了渔用电台发展现状,引出渔业通信网络建设及渔业通信设备建设上存在的问题,提出渔用电台设计需求,设计出一款数字化渔用电台。     

Advances in Digital Radio Systems

This paper examines the analog methods presently used in carrying digital signal via the terrestrial microwave radio relay systems. It then summarized the state of the art of two proposed digital radio systems, operating above and below 10 GHz. It also highlights some of the problem areas yet to be solved, with particular emphasis on these design problems associated with the high-capacity system. An extensive bibliography is given for easy reference.     

数字无线电广播技术探讨

随着我国音频广播的不断发展与创新,无线电技术被广泛应用于其中,发挥了很重要的作用。目前,我国的数字无线电广播技术尚未成熟,仍需要进一步地研究发展,以此满足人类的需要。文章主要对数字的无线电广播技术进行探讨分析,并对出现的问题提出解决措施。     

数字电视：技术强手试解中国迷题

中国数字电视推广的进程已经落后于当初制订的时间表,个中原因错综复杂.然而,不论产业链中的其他环节对于中国数字电视的未来的态度是画饼充饥,还是望梅止渴,抑或是逡巡观望,位于技术供应链上游的各半导体厂商一直是"时刻准备着",准备随时应对可能出现的市场爆发.     

无线电数字信号处理与软件无线电技术综述

在软件无线电技术中,宽带、多频段天线、高速数字信号处理、模数转换对于软件无线电技术而言都是关键技术,通过组合使用,达到设计目的以及应用要求。文中通过对数字信号处理以及无线电关键技术的处理两部分,分别论述,对其做出分析说明。     

数字储频器设计

介绍了一种数字储频器的设计方案。着重对方案的选择及关键性的指标进行了详细的理论分析。并给出了样板的初步测试结果。