COFDM: An overview (original) (raw)
Related papers
IEEE Transactions on Consumer Electronics, 1999
This paper compares the performances of ATSC 8-VSB and DVB-T COFDM transmission systems for Digital Television Terrestrial Broadcasting. The comparison is based on the most recent laboratory test results and theoretical analysis. Since there are more than one DTTB systems, many countries and administrations are now engaged in the process of selecting a DTTB system. Each country has specific characteristics and needs. The selection of a DTTB system must be based upon how well each of the modulation systems meets specific conditions such as spectrum resource, policy, coverage requirements and network structure, reception conditions, type of service required, objectives for program exchange, cost to the consumers and broadcasters. etc.
The COFDM modulation system: the heart of digital audio broadcasting
Electronics & Communication Engineering Journal, 1995
The COFDM modulation system: the heart of digital audio broadcasting by P. Shelswell Digital audio.broadcasting offers the potential to give every radio in Europe the sound quality of a compact disc. To accomplish this, it requires a rugged method of transmission. The coded orthogonal frequency division multiplexing (COFDM) modulation system was developed to meet this need. This paper describes the reasons why a new modulation process was needed, and explains how the COFDM system has been optimised to meet the requirements.
Performance evaluation of COFDM for digital audio broadcasting. I. Parametric study
IEEE Transactions on Broadcasting, 1997
This paper describes the performance of COFDM for digital audio broadcasti m u l~i p a~h mobile radio channels, CQF and modulation scheme which mitigates verse effects of fading by using wideband multicarrier tion coimbined with time interleaving and a convolutional error correcting code. A guard interval is inserted at the transition between successive symbols to absorb the ~n t e r s~b o l interference created by the time domain spread of the mobile radio channel. The decoding process is performed using d~ff~!rent~al demodulation in conjunction with a soft decision Viterbi decoder. The COFDM evaluation is done by means of coimputer simulations. A parametric study of the proposed COFDM system is done in this first of a series of papers to determine the optimal system parameter values for operation at ai radio frequency of 1.5 GMz The results show that the parameter values proposed in the standard are indeed well suited for operation at 1.5 GHz. Using the set of optimal parameter values found, the COFDM performance is then evaluated in mobile radio channels typical of different geogr:aphical environments. Simulation results confirm the benefit that the system gains from frequency diversity found in the urban and hilly terrain areas.
Efficient Terrestrial Digital Video Broadcasting Receivers Based OFDM Techniques
Przegląd Elektrotechniczny, 2021
This paper presents the design of efficient digital video propagation global receivers based on an orthogonal frequency distribution multiplexing scheme. The technology of DVB-T standards is developed by DVB assignment specifies the framing, modulation, channel, and noise elimination techniques for digital receiver television broadcasting. The OFDM scheme is a particular multicarrier transmission where a single information flow is transmitting in excess of a numeral of lesser speed sub-carrier with enough strength to radio channel effect. This paper provides a top-level simulation of the basic processing include in the transmitted and received OFDM waveforms under physical channel noise. The possibility to carry defined data containers in addition to audio and video transport streams has increased deployed for many services. The suggested structure of the classical digital broadcasting system was designed with permanent modulation methods which used to promise dependable communication even with very aggressive channel effects.. Streszczenie. W artykule przedstawiono projekt efektywnych globalnych odbiorników cyfrowej propagacji wideo w oparciu o schemat multipleksowania z ortogonalnym rozkładem częstotliwości. Technologia standardów DVB-T jest opracowywana przez przypisanie DVB, określające techniki ramkowania, modulacji, kanałów i eliminacji szumów dla nadawania telewizji cyfrowej. Schemat OFDM jest konkretną transmisją z wieloma nośnymi, w której pojedynczy przepływ informacji przesyła ponad liczbę mniejszej prędkości podnośnej z wystarczającą siłą dla efektu kanału radiowego. W tym artykule przedstawiono symulację na najwyższym poziomie podstawowego przetwarzania w przesyłanych i odbieranych kształtach fal OFDM w warunkach szumu kanału fizycznego. W wielu usługach wzrosła możliwość przenoszenia zdefiniowanych kontenerów danych oprócz strumieni transportowych audio i wideo. Proponowana struktura klasycznego cyfrowego systemu nadawczego została zaprojektowana z wykorzystaniem trwałych metod modulacji, które zapewniały niezawodną komunikację nawet przy bardzo agresywnych efektach kanałowych. (Wydajne naziemne odbiorniki cyfrowej transmisji wideo oparte na technikach OFDM)
Performance of Digital Video Broadcasting-Terrestrial (DVB-T) Using Ofdm as System
International Journal of Research in Engineering and Technology, 2016
In this paper the Performance of Digital Video Broadcasting-Terresrial(DVB-T) Transmission and reception part is undertaken.Any audio,video or image is taken as input and calculating the Bit Error Rate(BER) between transmitted and received image then we are analysing the performance of the system for different Signal To Noise Ratio(SNR) values. The system is analysed for different types of channels such as AWGN, Rayleigh and Rician channels. Finally a comparative study of the systems for different channel and SNR conditions is analysed. DVB-T is a system that makes use of the Orthogonal Frequency Division Multiplexing(OFDM) concept for the faster transmission and reception of the data. It also involves the error detection and correction techniques by the forward error correction techniques.
IEEE Transactions on Broadcasting, 2000
this paper compares the performances of the ATSC 8-VSB, the DVB-T COFDM, and the ISDB-T BST-OFDM digital television terrestrial transmission systems under different impairments and operating conditions. First, a general system level description is presented. It is followed by comparisons based on laboratory test results and theoretical analyzes. The differences in the system threshold definitions are discussed. In addition, a brief performance and implementation analysis is also presented for the three transmission systems under different network infrastructures. Whenever possible, the impact on the broadcasters or consumers is discussed. Possible performance improvements are also identified.
Orthogonal frequency division multiplexing (OFDM) is a special case of multicarrier transmission, where a single data stream is transmitted over a number of lower rate subcarriers. Orthogonal frequency division multiplexing (OFDM) has been chosen as modulation technique for different application wireless communications. OFDM can provide large data rates with sufficient robustness to radio channel impairments. The purpose of this paper is to provide a MATLAB simulation of the basic processing involved in the generation and reception of an OFDM signal in a physical channel and to provide a description of each of the steps involved. For this purpose, we shall use one of the proposed OFDM signals of the Digital Video Broadcasting (DVB) standard for the European digital television service i.e. Digital Video Broadcast-Terrestrial (DVB-T).
Implementation of Next generation DVB-T based OFDM in Modern Wireless Technology
2015
Now-a-days, life in the 24*365, in communication arenas video broadcasting is acting a key role. However, it is analyzed in terms of various wireless communication channels. Thus there is a need for development of next generation DVB-T. In OFDM the data is transmitted into parallel fashion by dividing high rate serial data into low rate sub-streams. By dividing the data into parallel streams the data rate is reduces, which results the increase of the length of symbol duration. The robustness of the channel and high data rates make OFDM as an efficient scheme for all the DVB-T applications and others applications too. So, we use one of the proposed OFDM signals of the Digital Video Broadcasting (DVB) standard which is now used for the European terrestrial digital television (DTV) service. In this paper, the advanced and proposed module of DVB-T system model is mentioned, based on the analysis of some parameters, which will discuss later in this paper, on the basis of FFT via differen...
HIGH PERFORMANCE OFDM SYSTEMS FOR DIGITAL VIDEO BROADCASTING-TERRESTRIAL (DVB-T)
Digital wireless communication has become one of the most exciting research topics in the electrical and electronic engineering field due to the explosive demands for high-speed wireless services, such as cellular video conferencing. Digital video broadcasting-terrestrial-second generation (DVB-T2) has been demonstrated to provide services with very high spectral efficiency and improved performance. Also, OFDM systems have been deployed in mobile networks for their spectral efficiency and optimum bit error rate. Among the OFDM systems, wavelet based systems have been demonstrated to have improved bandwidth and channel performance. In this paper the authors demonstrate that very high spectral efficiency, BER and PAPR can be achieved by employing DWT-DAPSK scheme with the DVTB-T2 system. It is demonstrated in this paper that including companding with this system results in further reduction of PAPR.