TxID Signal Research Articles

Transmitter Identification Signal Detection Algorithm for ATSC 3.0 Single Frequency Networks

To effectively operate and maintain an existing single frequency network (SFN), the advanced television systems committee (ATSC) 3.0 transmission system has utilized a transmitter identification (TxID) technique. The TxID technique aims is to obtain the channel impulse response (CIR) of each transmitter independently to support the adjustment of the relative power level and delay offset of individual transmitters. The professional receiver can detect such CIR, but a commercial ATSC 3.0 receiver does not need to be necessarily decoded the TxID signal. Also, according to the ATSC 3.0 standard, the TxID signal is embedded into the preamble signal with an appropriately low injection level (IL), such that the impact on the preamble reception is negligible. This paper proposes an efficient TxID signal detection algorithm to enhance the individual CIR detection performance during the TxID analyzing process. The simulation results indicate that the proposed TxID signal detection algorithm can offer better individual CIR detection performance as compared to the conventional TxID signal detection algorithms, even though the IL of TxID signal is low.

Detection Schemes for ATSC 3.0 Transmitter Identification in Single Frequency Network

Single frequency network (SFN) enables efficient use of spectrum by allocating the same frequency among multiple transmitters. In order to efficiently design and manage the SFN, the Advanced Television Systems Committee (ATSC) 3.0 physical layer standard has adopted transmitter identification (TxID) technology which allows to measure the individual and/or whole network channel response, such as power and time delay of the broadcast signal from transmitters. Since TxID is embedded into the host ATSC 3.0 frame as radio frequency (RF) watermark, it is transparent to legacy ATSC 3.0 receivers and only a specially designed TxID analyzer is able to detect it. This paper presents new TxID detection methods that improve the detection performance of ATSC 3.0 TxID signal by resolving the problems and limitation of the conventional TxID detection method. The superiorities of the proposed detection methods are verified through computer simulation, laboratory test, and field trial.

Selective Mapping for Robust Data Transmission Using TxID Signal

For Advanced Television Systems Committee (ATSC) digital terrestrial broadcasting systems, a transmitter identification (TxID) technique is introduced to analyze interference among broadcasting transmitters in single frequency networks (SFN). Based on the TxID analysis results, the transmit power and emission time delay of each broadcasting transmitter can be adjusted to minimize the effects of co- and adjacent- channel interference. For this reason, TxID has been recognized as an important feature in SFN configurations for ATSC 1.0 and 3.0 standards. Recently, there has been increasing interest in employing TxID for data transmission. This paper proposes a TxID based data transmission method for use with ATSC 1.0 and 3.0 standards. The major advantage of this data transmission method is its robustness while maintaining TxID properties. Simulations and laboratory tests demonstrate that the proposed technique can achieve a robust data transmission with backward compatibility to legacy ATSC 1.0 and 3.0 receivers.

ATSC 3.0 Transmitter Identification Signals and Applications

In the ATSC 3.0 PHY layer standard, a transmitter identification (TxID) signal is defined in order to provide the identification of an ATSC 3.0 transmitter. TxID signal can also be used to find the co-channel and adjacent interference signals, to assist accurate location finding calculation, and to obtain the channel estimation for each transmitter, which can help local service (e.g., targeted advertisement) reception, as well as for emergency alert. For efficient use of spectrum and quality of service improvement, single frequency network (SFN) where all transmitters share a single RF channel is often implemented. The recently developed ATSC 3.0 physical layer standard has been designed to support SFN. For efficient designing, fine-tuning and operating an SFN, it is crucial to identify each transmitter, as well as to adjust transmitting power and emission time of each transmitter. This paper presents TxID for ATSC 3.0, and analyzes its detection performance under very low signal to noise ratio environments and other applications, such as location finding, and channel estimation etc. for each SFN transmitter.

Additional Data Transmission Based on Sequence Phase Modulation for the ATSC Terrestrial DTV System

Several previous studies have demonstrated that additional low-rate data can be transmitted in Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) systems by modulating the polarity of the transmitter identification (TxID) signal. Previously proposed additional-data transmission schemes can offer an additional reliable transmission channel, and thus they have a very large coverage area compared to that of a DTV signal. Unfortunately, as the cost of a reliable transmission, they have a limitation in their maximum data rate. In this paper, we propose a new additional data transmission scheme based on sequence phase modulation (SPM) to increase the data rate. The proposed scheme exploits not only the polarity but also the phase of a TxID signal, and thus it significantly enhances the data rate compared to conventional schemes.

Injection-level optimisation for digital television transmitter identification systems using Kasami sequences

The transmitter identification (TxID) of digital television (DTV) systems becomes crucial nowadays. TxID (or transmitter fingerprinting) technique is used to detect, diagnose and classify the operating status of any radio transmitter of interest. The TxID system is specified in Advanced Television System Committee (ATSC) A/110 standard where pseudorandom sequences are proposed to be embedded into the DTV signals before transmission. The buried ratio or injection level of injected Kasami sequences in DTV-TxID systems will both affect the identification correctness and the DTV reception quality. In this study, the authors investigate the important unsolved optimisation problem for injection level. The authors present the new analysis here for the realistic scenario consisting of multiple transmitters and receivers over the additive white Gaussian noise channel. The signal-to-interference-plus-noise ratios for the TxID signal detection and the subject TV signal reception are both considered as two essential measures for single-frequency networks. Besides, the authors design a novel efficient injection-level optimisation scheme for TxID simply based on the given information including the signal-to-noise ratio at the receiver and the locations of the transmitters and the receiver(s).

RF Watermark Backward Compatibility Tests for the ATSC Terrestrial DTV Receivers

In a single frequency network (SFN) for the Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, co-channel interference induced by the multiple transmitters and/or repeaters which use the same output channel is inevitable. Since the presence of interference results in the performance degradation of the SFN, it is crucial to manipulate the interference by adjusting the transmit power and the emission time of each transmitter and repeater within the SFN. In the ATSC terrestrial DTV system, in order to facilitate the interference manipulation process, a transmitter identification (TxID) signal which is embedded in the transmit signal from each transmitter and repeater is recommended. However, such an embedded signal may degrade the DTV signal quality even though the injection level of the TxID signal is very low compared to the DTV signal. Hence, the effect of the TxID signal on the DTV signal needs to be investigated before deploying the SFN with TxID signal. In this paper, the effect of the TxID signal on the performance of legacy DTV receivers is investigated not only with extensive computer simulation but also with laboratory and field tests. According to the various test results, the average performance loss of the conventional DTV receiver due to the TxID signal is less than 0.2 dB when the TxID signal is injected at 30 dB below the DTV signal power.

A novel TxID insertion system for ATSC DTV auxiliary data transmission

This paper presents a new TxID (Transmitter Identification) data insertion system for ATSC DTV auxiliary data transmission. Because the functional description of TxID was not included in the early ATSC transmission standard, most of the conventional DTV transmitters and translators cannot transmit TxID signal which should be generated during 8-VSB (Vestigial Side Band) symbol generation process. The proposed system generates RF signal of TxID and then combines it synchronously with the RF signal of the legacy ATSC transmitter. This combination enables the conventional DTV transmitters and translators to transmit TxID signal with auxiliary data based on RF watermark technique. The proposed system is implemented and its performance is evaluated through laboratory tests.

ATSC 지상파 DTV 시스템에서 TxID를 이용한 부가데이터 전송 기법

ATSC (Advanced Television Systems Committee) 지상파 DTV 시스템에서 단일 주파수 망 (Single Frequency Network) 구성 시 동일한 주파수 대역을 사용하는 다수의 송신기와 중계기들로 인하여 수신기에서는 필연적으로 간섭이 발생하게 된다. 이러한 간섭 문제를 해결하기 위하여 ATSC recommended practice (RP) A/111에서는 Kasami 수열로 구성된 송신 식별 (Transmitter Identification, TxID) 신호를 각 송신기 및 중계기에 할당하고 이를 송신 신호에 부가하여 전송한다. 본 논문에서는 TxID 신호로 제안된 Kasami 수열의 극성 및 위상을 조절하여 부가데이터를 전송하는 기법을 제안한다. 제안하는 기법에서 Kasami 수열은 송신기 및 중계기를 식별하기위한 TxID 신호로서의 기능을 수행할 뿐만 아니라 추가적으로 부가데이터를 전송할 수 있는 장점이 있다. In a Single Frequency Network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences induced by the multiple transmitters and/or repeaters using same frequency are unavoidable. To ease the interference handing in the SFN for ATSC DTV system, transmitter identification (TxID) signal is recommended in the ATSC terrestrial DTV system. The TxID signal is embedded in the ATSC DTV signal and transmitted from each transmitter and repeater within the SFN and in ATSC recommended practice (RP) A/111, Kasami sequence is recommended as the TxID signal. In this paper, we propose an additional data transmission scheme using the TxID signal. In the proposed scheme, the Kasami sequence not only acts as the conventional TxID of the SFN for ATSC terrestrial DTV system but also carriers the additional data bits on its polarity and the code phase.

ATSC DTV 시스템에서 TxID 신호가 기존 수신기에 미치는 영향 분석

ATSC 방식의 지상파 디지털 TV 방송에서는 단일 주파수 망 구성 시 송신기들과 중계기들이 동일한 주파수를 사용함에 따라 수신기에서 간섭 문제가 발생한다. 이를 해결하기 위하여 ATSC 에서는 각 송신기 및 중계기에 송신기 식별 (TxID: Transmitter Identification) 신호를 할당하여 송신 및 중계 신호에 부가하여 전송하도록 권고하고 있다. 본 논문에서는 기존 DTV 신호에 부가되어 전송되는 TxID 신호가 기존의 상용 수신기에 미치는 영향을 전산실험, 실험실 테스트, 그리고 필드 테스트를 통해 살펴본다. 이러한 테스트 결과에 의하면 TxID 신호가 기존 DTV 신호보다 30 dB 이하의 삽입레벨로 부가하여 전송될 때 상용 DTV 수신기의 TOV(Threshold of Visibility) 의 증가량은 0.17 dB 보다 작았다. 이것은 TxID 신호를 30 dB이하로 부가하여 전송하면 기존의 상용 수신기에 미치는 영향이 거의 없음을 의미한다. When we implement the single frequency network (SFN) in ATSC terrestrial DTV system, there is an interference problem to DTV receivers due to the use of same frequency channel among transmitters and repeaters. To resolve this problem, it is recommended to adopt the transmitter identification signals in transmitting equipments. In this paper, we analyzed the influence suffered by legacy DTV receivers when the TxID signal is added to the DTV transmitting signals and the results were further verified by computer simulation, laboratory test and field test. The above tests show that if the TxID signal is added to the level of -30dB compared to the original DTV signal, the TOV(Threshold Of Visibility) increment in legacy receivers is about 0.17 dB. It means that we can insert and transmit the TxID signal in ATSC terrestrial DTV system without making the negative effect to the legacy DTV receivers.

An Efficient Receiver Structure for Robust Data Transmission using TxID Signal in the ATSC DTV System

In a single frequency network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences due to the multiple transmitters and/or repeaters using same frequency is inevitable. This interference problem can be solved by adjusting transmit power and time of each transmitter and repeater within a SFN. To assist this process, a transmitter identification (TxID) signal, which is embedded in the transmit signal from each transmitter or repeater, is recommended in the ATSC terrestrial DTV system. In this paper, we investigate the previous proposed robust data transmission schemes using the TxID signal and propose an efficient receiver structure for detection of the embedded data in TxID signals. Based on the laboratory test, we verify that the proposed scheme offers an additional reliable communication link supporting up to 160 bps data rate, which is at least 13 dB robust compared to the conventional DTV system.

분산 중계기 Part 2: 실험실 테스트 결과

본 논문에서는 ATSC (Advanced Television Systems Committee) 지상파 디지털 TV 방송 방식에서의 분산 주파수 망(distributed frequency network)을 위해 개발된 분산중계기(Distributed Translator: DTxR)에 대한 실험실 테스트 결과를 기술하고, 그 결과를 분석한다. DTxR 실험실 테스트는 수신부 테스트와 송신부 테스트로 구분된다. DTxR 수신부 테스트는 dynamic range, 랜덤 잡음, 단일 에코, 인접채널 신호의 간섭 테스트 등을 포함하고, DTxR 송신부 테스트는 출력신호의 품질(대역외 방사, 송신 품질, 위상잡음), 출력신호들의 주파수 일치, TxID (Transmitter Identification) 신호가 상용 수신기에 미치는 영향 평가 등을 포함한다. 실험실 테스트 결과에 의하면, DTxR 수신부는 0~17 us 범위 내의 평균 -2.5 dB의 단일 에코 신호를 제거하며, 랜덤 잡음에 대한 TOV (Threshold of Visibility)는 평균 17.5 dB이다. 또한, DTxR 송신부 출력 신호는 미국의 FCC (Federal Communications Commission) 규격을 만족하며, DTxR 출력신호들의 주파수 차이는 0.001 Hz 보다 작다. This paper presents and analyzes laboratory test results of distributed translator (DTxR) for distributed frequency network (DFN) in the ATSC (Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The DTxR laboratory test is classified to receiving part test and transmitting part test. The receiving part test includes dynamic range, random noise, single echo, and adjacent channel interference. The transmitting part test includes quality of output signal (out-of channel emission, quality of transmitting signal, and phase noise), frequency synchronization among output signals, and TxID (Transmitter Identification) signal's affect to the legacy receiver. By the laboratory test results, the receiving part of DTxR eliminates average -2.5 dB of single echo and has average 17.5 dB at TOV (Threshold of Visibility) under random noise environment. In addition, the transmitting part of DTxR satisfies the specification of US FCC (Federal Communications Commission), and frequency difference among DTxR output signals is less than 0.001 Hz.

Transmitter Identification Signal Analyzer for Single Frequency Network

A Single frequency network (SFN) design based on the Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system normally causes interference among signals from multiple transmitters or repeaters in the network. The ATSC recommended practice (RP) A/111 introduces transmitter identification (TxID) signals embedded to the ATSC 8-VSB signals. A TxID signal analyzer is then used to detect the TxID signals and analyze the network. Following the analysis results, the SFN design can be managed by adjusting delay and power of multiple transmitters and repeaters. This paper presents basic concept of the Kasami sequence used as the TxID signals, and their insertion method to the ATSC 8-VSB signals. The structure of the TxID signal analyzer to efficiently detect TxID signals is proposed, and a theoretical approach to performance measurement of the TxID signal analyzer is discussed. In addition, computer simulation and laboratory test results are provided to evaluate the performance of the TxID signal analyzer.

송신기 식별 신호분석기

ATSC 방식의 지상파 디지털 TV 방송에서는 단일 주파수 망(Single Frequency Network: SFN) 구성 시 단일 주파수 사용에 따른 인접 송신기 혹은 중계기에 대한 간섭 문제가 발생한다. 이를 해결하기 위해 ATSC 권고에서는 각 송신기 및 중계기에 식별(Transmitter Identification: TxID) 신호를 할당하여 송신 및 중계 신호에 부가하여 전송하고, TxID 신호분석기를 통하여 각 송신기 및 중계기에 의해 발생되는 채널환경을 검출하여 망을 제어한다. 본 논문에서는 TxID 신호로 사용되는 Kasami 수열의 생성 및 DTV 신호로의 삽입방법에 관해 살펴보고, TxID 신호의 효율적인 분석을 위한 TxID 신호분석기의 구조를 제안한다. 또한, 수학적인 분석을 통해 제안된 TxID 신호분석기의 성능을 고찰하고, 전산실험 및 실험실 테스트를 통해 제안된 TxID 신호분석기의 성능을 검증한다. Single frequency network (SFN) design based on the Advanced Television Systems Committee (ATSC) specification, a terrestrial digital television (DTV) system, normally causes a interference problem, among signals from multiple transmitters or repeaters. To solve this, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal embedded in a signal from each transmitter or repeater. A TxID signal analyzer is then used to detect the TxID signal, and following the analysis results, a SFN design can be adjusted. This paper discusses the generation and usages of Kasami sequence, is used the TxID signal. The configuration of the TxID signal analyzer to efficiently detect TxID signal is proposed and the results of theoretical performance analysis are provided. Moreover, computer simulation and laboratory test results are provided to evaluate the performance of TxID signal analyzer and the theoretical performance analysis.

A New Position Location System Using DTV Transmitter Identification Watermark Signals

A new position location technique using the transmitter identification (TxID) RF watermark in the digital TV (DTV) signals is proposed in this paper. Conventional global positioning system (GPS) usually does not work well inside buildings due to the high frequency and weak field strength of the signal. In contrast to the GPS, the DTV signals are received from transmitters at relatively short distance, while the broadcast transmitters operate at levels up to the megawatts effective radiated power (ERP). Also the RF frequency of the DTV signal is much lower than the GPS, which makes it easier for the signal to penetrate buildings and other objects. The proposed position location system based on DTV TxID signal is presented in this paper. Practical receiver implementation issues including nonideal correlation and synchronization are analyzed and discussed. Performance of the proposed technique is evaluated through Monte Carlo simulations and compared with other existing position location systems. Possible ways to improve the accuracy of the new position location system is discussed.