Transmitter Identification Research Articles

Augmented Data Transmission for the ATSC Terrestrial DTV System

In this paper, we propose a novel Augmented Data Transmission (ADT) system which can transmit an additional data stream in the Advanced Television Systems Committee (ATSC) terrestrial DTV system. The proposed ADT system can offer an additional data of rate up to a few megabits per second (Mbps) based on hierarchical modulation, DTV signal cancellation, and advanced error correction code. The proposed ADT system significantly enhances capability compared with the data transmission schemes used in the transmitter identification (TxID) system. Since the proposed ADT system uses the in-band hierarchical modulation, it does not require any additional RF spectrum to increase the data capacity in a 6 MHz RF channel. Meanwhile, the ADT system has negligible impact to legacy receivers, if the proposed ADT system is deployed over the frequency bands occupied by ATSC A/53 or A/153 services.

단말기 위치 자동 인식을 이용한 T-DMB 자동재난경보서비스

본 논문에서는 재난 지역을 고려한 T-DMB 자동재난경보서비스 수신 모델을 제안한다. 제안한 수신 모델에서는 T-DMB 신호를 수신하고 있는 단말기의 위치를 자동으로 파악한 후, 단말기가 재난이 발생한 지역과 밀접한 위치에 있을 경우에만 재난 메시지를 단말기에 표시한다. 단말기의 위치를 파악하기 위해서는 먼저 T-DMB 전송 프레임 중 동기 채널(synchronization channel, SC)의 널 심볼(null symbol)에 포함된 중계기 정보인 TII (transmitter identification information) 신호로부터 중계기의 식별 정보를 획득한 후, 이 값을 중계기의 위치 정보가 전송되는 FIG 0/22의 데이터 필드에서 찾아 해당 중계기의 위치를 계산한다. 이와 같이 계산된 중계기의 위치를 단말기의 위치로 설정하고, 이를 재난이 발생한 지역과 비교하여 인접한 지역일 경우에만 해당 재난 메시지를 단말기에 표출한다. 이를 검증하기 위한 실험에서는 테스트용으로 제작된 재난 메시지들을 T-DMB 송출기를 통해 실제 송출하여 테스트를 진행하였다. This paper presents T-DMB AEAS (automatic emergency alerting service) receiver model considering emergency region. The proposed receiver model determines the geographical location of the terminal by analysing the received T-DMB signal and displays the AEAS messages only if the location of terminal is similar to the emergency site. First, to determine the geographical location of the terminal, we extract the TII value from the null symbol of the SC and, based on it, calculate the location of transmitter by analysing FIG 0/22 delivering the TII-related data. The proposed algorithm sets the location of transmitter as that of receiver and displays the emergency message only in the case of the similar region. The experiment was conducted in the test environment of low power T-DMB generator based on the T-DMB AEAS messages.

A Novel Data Transmission Scheme for ATSC Terrestrial DTV Systems

In Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) systems, additional very low-rate data can be transmitted by modulating the amplitude and polarity of the transmitter identification (TxID) signal. Although the additional data transmission scheme offers reliable transmission and has a very large coverage area, it has a limitation on the data rate. In this paper, we propose a novel additional data transmission scheme based on the TxID sequences of the ATSC DTV system and Walsh modulation. The proposed scheme not only increases the data rate significantly, but also offers a virtually identical coverage area compared to a conventional scheme.

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).

Signal Cancellation Techniques for RF Watermark Detection in an ATSC Mobile DTV System

The popularity of Advanced Television System Committee (ATSC) mobile digital television (DTV) [mobile/handheld (M/H)] cultivates a fast growing demand on transmitter identification (TxID) in a mobile environment. The ATSC A/110 standard addresses this need with a TxID system using a radio-frequency (RF) watermark. This paper studies the use of DTV signal cancellation techniques in RF watermark detection. In particular, we develop two schemes, namely, decision feedback convolution and decision feedback equalizer (DFE) decision-directed (DD) error, to meet different application scenarios. The first scheme is designed for static and slow-fading channels, whereas the second scheme is designed for dynamic and fast-fading channels. We have conducted computer simulation on TxID over various channel conditions to evaluate the performance of our schemes. Numerical results show that DTV signal cancellation can significantly boost the signal-to-noise (SNR) level of RF watermark and thus reinforce TxID in a mobile environment.

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.

Study on the Techniques on Extracting Carrier Frequency Stability of Individual Communication Transmitter Identification

摘要: 由于电台频率稳定度较高，造成电台个体之间的频率波动特征差别较小，因此需要精确的频率稳定度提取技术，而目前常规信号频率提取方法获取的频率稳定度特征难以达到精度要求。该文重点研究了频率稳定度的有效提取技术，提出了3种有效的提取方法，在详细分析基本原理基础上，进行了仿真实验，比较精确地获取了载波频率稳定度信息，最后利用实际电台进行了验证，结果表明算法的有效性。 关键词: 频率稳定度 / 细微特征 / 特征提取 / 个体识别

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.

Consistency of weighted feature set and polyspectral kernels in individual communication transmitter identification

This paper presents a method using support vector machine with polyspectral kernels for classification of individual transmitters. Then, the neighborhood-rough-set-based weighted feature set is proposed. The experiments of the algorithms mentioned above indicate that they have consistency, which raises a new weighted kernel. The experiment shows that better classification rate can be achieved.

Network Design and Field Application of ATSC Distributed Translators

In this paper, a design method for a distributed translator network considering the equalization window of commercial receivers is presented and compared with the field application results with three distributed translators in an urban area of Seoul, Korea. Proper transmission timing to minimize pre-ghost can be derived from the proposed design method. With designed timing information and the measured TxID (Transmitter Identification) information, the transmission timings of translators can be adjusted. Three types of receivers with different chipset generations were used for this field test. Several combinations of translators were applied for the analysis of the effect of operating multiple translators. Field test results are analyzed and discussed for the evaluation of the target distributed translator network and its design method.

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.

분산 중계기 Part 1: 분산 중계 기술

본 논문에서는 ATSC (Advanced Television Systems Committee) 지상파 디지털 TV 방송 방식에서의 분산 주파수 망(distributed frequency network: DFN)의 특징 및 기술적인 요구 사항에 관해 고찰하고, 그 요구사항을 만족하기 위한 분산중계기(Distributed Translator: DTxR)를 제안한다. DFN은 송신기와 중계기는 서로 다른 주파수를 사용하지만 동일한 송신기 신호를 중계하는 모든 중계기들 간에는 동일한 주파수를 사용하는 방송망이다. 또한, 본 논문에서는 DTxR 구현을 위한 복조, 등화, TxID (Transmitter Identification) 생성 및 삽입, 변조, 그리고 중계기간 주파수 일치 등과 같은 신호처리 기술을 소개한다. This paper considers technological requirements to broadcast digital television signals using distributed frequency network (DFN) in the advanced television systems committee (ATSC) transmission system and proposes distributed translator (DTxR) to meet such requirements. In the DFN, DTxR uses different frequency from main transmitter, but same among DTxRs. In addition, this paper introduces digital signal processing (DSP) techniques, which consist of demodulation, equalization, transmitter identification (TxID) generation and insertion, and modulation, to implement DTxR.

Transmitter Identification With Watermark Signal in DVB-H Signal Frequency Network

Transmitter identification (TxID) technique is used to diagnose the operating status of radio transmitters in DTV distributed transmission network. In this paper, a new kind of TxID method for DVB-H SFN(single frequency network)system is proposed. We embed a signal (e.g. watermark) in the DVB-H signal to form the composite signal. The embedded signal will not alternate the system spectral efficiency. By watermarking theory, we demonstrate the required embedded level for watermarking signal to achieve a given bit error probability in different circumstance. Simulation results show that the receiver can distinguish the watermarking signal with low embedding strength even in wireless situation. At that embedding strength, BER performance degradation for the receiver can be ignored.

Reception Power Estimation Using Transmitter Identification Signal for Single Frequency Network

In a single frequency network (SFN) based on the Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, receivers inevitably suffer from the interference generated by using the same frequency among multiple transmitters or repeaters. The amount of the interference can be handled by adjusting transmit power and time of each transmitter and repeater. Hence, it is crucial to estimate the individual reception power from each transmitter or repeater at the given point of interest. This paper presents an efficient method to estimate the individual reception power from each transmitter or repeater. The field test results are provided to evaluate the proposed method. The proposed method exploits the transmitter identification (TxID) signals which are embedded in existing 8-VSB signals.

Robust Emergency Communications Using TxID Watermark of ATSC DTV System

In today’s world, having a reliable communication system during emergency situations is of paramount importance to lessen the impact of the disasters. This paper proposes an emergency communication technique which is enabled by ATSC DTV transmitter identification (TxID) watermark signal. Theoretical and simulation results show that ATSC TxID watermark signal can reach a larger coverage area than the 8-VSB DTV signal and hence can be used to enable emergency communication during national disastrous situations. The coverage for this emergency communication system is predicted using popular Hata-Davidson propagation model and coverage maps clearly showing the extended and overlapped coverage for DTV stations in Huron and Stratford area in the province of Ontario, Canada is presented. Comparison with other existing emergency communication systems is carried out and performance matrices such as alerting message error rate, required no. of stations, network reliability etc. are evaluated to assess the robustness of the proposed emergency communication system.

TxID 신호를 이용한 수신전력 추정

In a single frequency network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interference due to the use of same frequency among multiple transmitters or repeaters is inevitable for receivers. This problem can be solved by adjusting transmit power and time of each transmitter and repeater. To adjust SFNs, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal which is embedded in a signal from each transmitter or repeater. This paper proposes an efficient method to estimate the individual reception power from each transmitter or repeater based on the channel profile of SFN and the total reception power. Moreover, field test results are provided to evaluate the performance of the proposed method.

Watermark in the digital video broadcasting handheld transmission signal

Transmitter identification (TxID) technique is used to diagnose the operation status of radio transmitters in DTV distributed transmission network. A new TxID method for digital video broadcasting-handheld (DVB-H) system is proposed. Watermark is embedded in the DVB-H signal to form the composite signal. According to watermarking theory we demonstrate the required signal level for watermarking signal to achieve given bit error probability under different circumstance. By selecting the reference pattern to generate watermarking signal, peak-to-average power ratio (PAPR) of the transmitted signal can be improved. Simulation results show that even in wireless situation the receiver can distinguish the watermarking signal with low embedding strength, and distortion to the host signal can also be ignored.