Radio Data System Research Articles

Safety of driver interaction with in-vehicle information systems

Advances in vehicle instrumentation are driven by customer demand, by the desire of manufacturers to add value and by technology that offers increasingly sophisticated and cost effective options. The range of information and communications equipment available to the driver has grown considerably over the past 5 years. Trip computers and radio data systems (RDS) are now standard on many vehicles, and the use of in-vehicle telephones has also increased. Other driver information products, such as congestion warning and route guidance systems, are becoming increasingly common. Much development of in-vehicle information has, necessarily, focused on getting the technology to work. Now, as products are emerging, the real needs of drivers and their interaction with new systems is receiving much greater attention. The human-machine interface (HMI) is emerging as a key area that has a significant impact on the overall usability and safety of in-vehicle systems. This paper discusses HMI safety and how it is being addressed through standards, codes of practice and design guidelines.

Developing a Location Database for the UK Radio Data System – Traffic Messaging Channel Service

This paper deals with the development of a location database compatible for use with the proposed Radio Data System – Traffic Messaging Channel for Great Britain. It looks at the needs for such a database and the technical difficulties that have been overcome in developing a cost-effective, automatic, production system that provides the most detailed roads location database in Great Britain.

Ein anwendungsspezifischer Schaltkreis zum Senden und Empfang von Radio-Data-System(RDS)-Signalen

The Radio Data System (RDS) intends to improve functionality of FM receivers. Additional information - e. g. call sign, tuning frequency, alternative frequencies, time and date, traffic information, public or encrypted messages,... - can be transmitted during stereophonic or monophonic VHF/FM sound broadcasts. An ASIC is described which can receive or transmit RDS-data-patterns in a standalone or a microprocessor-based environment. Working as a transmitter or as a pattern-generator, the ASIC is able to encode and transmit RDS messages without any microprocessor support. A maximum sequence length of 64 kByte of data can be loaded from an external EPROM using on-chip direct memory access counters. Working as a receiver, the ASIC will detect block synchronisation, receive RDS data blocks and correct errors without any software overhead. A data block is checked and validated in less than five microseconds. An integrated FIR-filter detects valid block sequences immediately, even in the precence of random data which produces false synchronisation pulses on average five times per second. Last not least, due to its extended addressing capabilities, the ASIC can be used as a memory address expander when small single chip microprocessors with limited RAM will have to read and store RDS data during a longer perlod of time. Target technology is 0.8 μm CMOS, the ASIC utilizes the equivalent of 80 k MOS-Transistors.

Polarisation diversity in high frequency radio datasystems

The authors describe the results of a series of experiments to quantify the potential advantage of polarisation diversity as applied to a 2.4 kbit/s HF data system. Two configurations of polarisation diversity were tested: one using two orthogonal antennas at the transmitting end, and a second using two orthogonal elements at the receiving end. The performance of these systems was compared with a system using a single antenna at each end. The results indicate that a significant increase in performance can be obtained through the use of polarisation diversity and was found to reduce the error rate by ~two to four orders of magnitude in most cases.

A broadcast synthesized FM modulator with a radio data system encoder

The design and development of a broadcast FM modulator with a RDS (radio data system) encoder is presented. The system is fully coherent with the modulated RF frequency synthesized in the 875-108 MHz frequency band with 100 kHz frequency steps. This feature has been obtained by a feedback loop where a PLL acts as a frequency demodulator, thus providing control capability on the phase noise of the modulated signal without any restrictions in the modulation bandwidth, thereby reducing the adjustments when a frequency change is made. The design of the RDS encoder has been done according to the CCIR regulations, avoiding the BPSK approach, by means of current electronic circuits plus a switch-capacitor filter in a simplified implementation derived from the RDS standard and suitable for an eventual ASIC design. The developed system gives a full capability as a FM stereo broadcast modulator according to the CCIR regulations, in order to be used in a university broadcast station for testing and developing all the features of the RDS system, specially the use of the transparent data channel as a communication method between the university community.

Overview of wireless personal communications

This article presents an overview of the current state of wireless communications, including relevant ongoing activities in technology development, standards, and spectrum allocation. The authors discuss cellular radio, cordless telephony, and wireless data systems. Ongoing and planned future developments are summarized. The presentation is oriented toward broad coverage rather than technical depth. However, brief discussions of the air interfaces for existing digital cellular and digital cordless systems are provided, because the air interface bears heavily on system capacity and the environments in which the system can be used, as well as on the cost and complexity of the equipment.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Analysis of new methods for broadcasting digital data to mobile terminals over an FM-channel

Two new methods using an FM-radio channel for transmission of digital data to mobile terminals are examined: 1. A modification of the radio data system (RDS). In RDS, additional digital information is multiplexed with a stereo sound signal. A new system is suggested where the data signal can be multiplexed with a mono audio signal. This causes extension to the bandwidth available for the data signal, and therefore the RDS bitrate can be increased. Error calculations are performed both for the original RDS system and for the new system. 2. Orthogonal frequency division multiplexing (OFDM). OFDM is used in the digital audio broadcasting system (DAB), which is designed to transmit digital audio in the FM band. In OFDM a signal is divided over a large number of 2- or 4-PSK modulated orthogonal subcarriers. The subcarriers of 6 different programmes are multiplexed in one beam to reduce the effects of frequency selectivity of the transmission channel. A new system based on OFDM is proposed, in which the carriers of each programme are transmitted in one FM-channel with a bandwidth of 200 kHz instead of multiplexed with the carriers of other programmes. Error calculations are performed for the subcarriers used in the OFDM modulation method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Development of DARC decoding LSI for high-speed FM subcarrier system

Expectations have been running high for a new generation of FM broadcasting systems targeted at mobile FM reception, notably in cars. The DARC (data radio channel) is an FM multiplex broadcasting system designed to address these expectations. When compared with the RDS (radio data system) and the RBDS (radio broadcast data system) which have already gone into service in Europe and the United States, the DARC system features an over-tenfold transmission capacity. Other features include the L-MSK (level-controlled minimum shift keying) modulation system, the incorporation of powerful error-correction code, a wide service area, and so forth. In developing LSIs, we have set the following three major goals: ease of incorporation into FM receivers, elimination of adjustments, and minimization of add-on components. >

Spectrum efficiency of radio data system (RDS)

The paper addresses the use of the radio data system (RDS) for datacasting road traffic information. It is concluded that, although RDS may be essential to the early phases of introduction of novel advanced traffic information systems (ATISs), FM subcarrier transmission does not offer a spectrum-efficient solution for large-scale ATIS datacasting. The conclusions are believed relevant to the spectrum-efficient design of the future datacasting networks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

TRAFFIC INFORMATION SERVICES USING FM MULTIPLEX BROADCASTING

NHK has developed an FM multiplex broadcasting system using a new digital modulation method called level controlled minimum shift keying (L-MSK) which is a kind of MSK. This system is multipath-proof, and has a transmission capacity of 16 kbps. Moreover, it has a compatibility with radio data system (RDS) because they use different frequency bands. Transmission tests were carried out to measure the performance of the 16 kbps L-MSK system in the service area of the NHK Tokyo FM station. These tests revealed that this system was superior to RDS in terms of the correct reception rates obtained in mobility. FM multiplex broadcasting using L-MSK has many merits for traffic information services.

Digital modulation scheme for FM multiplex broadcasting with mobile reception

AbstractThe FM multiplex broadcasting is one of the broadcasting configurations for providing a new service, where digital signals are multiplexed by utilizing the empty spectrum of the baseband signal in the FM stereo broadcasting. The fixed reception FM multiplex broadcasting system, where reception is done by setting up an antenna has already been developed and used in practice, and its broadcasting has been started. On the other hand, it would be desirable to develop a mobile reception FM multiplex broadcasting system with a certain amount of transmission capacity, where the broadcast can be received by a car or portable radio, for an application to the traffic information transmission. As to the digital transmission to moving objects, interferences such as fading and multiple paths are known to be present and the technical difficulty is increased with the increase of the bit rate. Furthermore, there are difficulties in the FM multiplex broadcasting such as the cross‐talk from the sound signal, due to the nature of the multiplex signal. Only a very low bit‐rate system of about 1 kbit/s has been developed such as RDS (Radio Data System) [1] in Europe for practical applications to the mobile reception. This study aims at the development of a mobile reception FM multiplex broadcasting system with a higher bit rate. An FM multiplex transmission simulator is constructed first, and the transmission characteristics inherent to the FM multiplexing are analyzed. A digital modulation method suited to these transmission characteristics is presented. By laboratory and field transmission tests, the effectiveness of the proposed digital modulation scheme is demonstrated.

An in-receiver database-the critical factor in RBDS

The in-receiver database system (I-RDS) of the radio broadcast data system (RBDS) is described. I-RDS is designed to offer the following main features to the radio listener: (1) automatic identification of any station by call letters, frequency, location (city, state), and format (program type) and (2) format-scanning, i.e., the ability to tune to any station by selecting the type of music or program usually broadcast by the station. I-RDS is important to the market acceptance of RBDS since it is only with its implementation that all 13000+ North American stations in both AM and FM can be automatically identified and instantly accessed through format-scanning. >

Reliability testing method for RDS based on the PI code statistics

A novel method, called PICS (program identification code statistics), for testing the reliability of data transmission in the RDS (Radio Data System) for VHF/FM sound broadcasting is proposed. PICS tests RDS during the normal operation mode. Statistical tests are performed on the part of the RDS message named the PI code (program identification code), which contains permanent information and is transmitted periodically. Computer simulation of data transmission was performed to calculate the statistical parameters for the whole RDS message and the PI code. Results are compared with linear regression analysis. The influence of white noise and multipath propagation on the variation of the statistical parameters was tested. It is shown that PICS is effective in testing the statistical properties of RDS.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An analog BiCMOS integrated circuit for front-end RDS decoder

An analog integrated front-end circuit for the RDS (Radio-Data-System) digital decoder is described. The core of the circuit is an 8th-order switched-capacitor (SC) bandpass filter at 57 kHz with linear-phase response in a 3 kHz bandwidth. A low-offset comparator provides the squared signal for the digital decoder. Antialiasing and smoothing filters are also included in the chip, as well as the clock generation for the SC section; few external components are required. Integrated in a high-performance BiCMOS technology, the circuit operates from a single 5-V supply and dissipates 45 mW. The die size is 5 mm/sup 2/.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

VHF-FM receiver secondary services: RDS to ARI compatibility topics

The authors investigate the mutual compatibility of the usual traffic announcement analog secondary broadcasting ARI (auto radio information) service and simultaneous digital secondary service, known as the radio data system (RDS), evaluating cross-interferences in the standard VHF-FM receiver without coherent detection. On the basis of the analysis and computer simulation the authors conclude that full compatibility of the RDS and ARI systems is possible solely by quadrature procedures both at the transmitting and receiving sides. This implies coherent detection at the receiving side of the circuit for both RDS and ARI signals. The compatibility of the already existing ARI receivers (using an envelope detector) with the RDS system is not ideal. The worst case occurs when some broadcast transmitter broadcasts only RDS signals (without ARI signals). The compatibility of an only-ARI receiver for the reception of RDS+ARI signals depends primarily on the bandpass width of the filter for separation of signals and 57-kHz subcarrier. >

Towards real-time implementation of a radio-data system for AM sound broadcasting

A new modulation scheme for AM sound broadcasting is being studied which allows an additional data signal to be transmitted without significant envelope distortion or increase in bandwidth. The data signals carry information that can be used by specially-equipped receivers for various display and control functions. The proposed radio-data system concerns services for medium or high frequency broadcasting where AM predominates. A real-time implementation of the proposed system using a digital signal processor (TMS 320) is described, and experimental results for sinusoidal envelope modulation are presented. Measurements of the spectrum of the resulting signal show more than 40 dB rejection of out-of-band components, relative to the carrier.

RDS. The way ahead for radio

Radio data systems will enable the listener to ‘programme’ a radio to hunt for news or travel information and eliminate the need for manual retuning

Automatic Tuning Car Radio Based on the Radio Data System

The radio data system (RDS) is a standard[1] for transmission of supplemental information for FM sound broadcasting. This standard was agreed upon by the European Broadcasting Union in 1984.

Development of Radio Data System Decoder IC's

The radio Data System RDS is the multiplex transmission system of Tuning Aid and other messages with the VHF/FM broadcasting. The specifications of the RDS were published by EBU (European Broadcasting Union) in March, 1984, (1). The regular broadcasting of RDS is being executed in Sweden. It will begin in U.K. in September, 1987, and in W. Germany in April, 1988. Other European countries will follow these countries.

The impact of radio-data on broadcast receivers

For some years the BBC and other European broadcasters have been investigating systems for broadcasting radiodata labels from v.h.f. radio-broadcast transmitters. These data signals are primarily intended to aid radio listeners in tuning their receivers to a desired station orprogramme. Other applications, such as the transmission of simple messages, are also envisaged. Although no firm specification for radio-data has yet been agreed by European broadcasters, recent international field-trials of various proposed radio-data systems were a significant milestone in the development of a standardized radio-data system. These field-trials also confirmed that reliable radio-data reception is possible with low-cost receiver/decoders even under very adverse reception conditions.