9 research outputs found
Analysis and Performance Comparison of DVB-T and DTMB Systems for Terrestrial Digital TV
Orthogonal frequency-division multiplexing (OFDM) is the most popular
transmission technology in digital terrestrial broadcasting (DTTB), adopted by
many DTTB standards. In this paper, the bit error rate (BER) performance of two
DTTB systems, namely cyclic prefix OFDM (CP-OFDM) based DVB-T and time domain
synchronous OFDM (TDS-OFDM) based DTMB, is evaluated in different channel
conditions. Spectrum utilization and power efficiency are also discussed to
demonstrate the transmission overhead of both systems. Simulation results show
that the performances of the two systems are much close. Given the same ratio
of guard interval (GI), the DVB-T outperforms DTMB in terms of signal to noise
ratio (SNR) in Gaussian and Ricean channels, while DTMB behaves better
performance in Rayleigh channel in higher code rates and higher orders of
constellation thanks to its efficient channel coding and interleaving scheme
A Novel Data-Aided Channel Estimation with Reduced Complexity for TDS-OFDM Systems
In contrast to the classical cyclic prefix (CP)-OFDM, the time domain
synchronous (TDS)-OFDM employs a known pseudo noise (PN) sequence as guard
interval (GI). Conventional channel estimation methods for TDS-OFDM are based
on the exploitation of the PN sequence and consequently suffer from intersymbol
interference (ISI). This paper proposes a novel dataaided channel estimation
method which combines the channel estimates obtained from the PN sequence and,
most importantly, additional channel estimates extracted from OFDM data
symbols. Data-aided channel estimation is carried out using the rebuilt OFDM
data symbols as virtual training sequences. In contrast to the classical turbo
channel estimation, interleaving and decoding functions are not included in the
feedback loop when rebuilding OFDM data symbols thereby reducing the
complexity. Several improved techniques are proposed to refine the data-aided
channel estimates, namely one-dimensional (1-D)/two-dimensional (2-D) moving
average and Wiener filtering. Finally, the MMSE criteria is used to obtain the
best combination results and an iterative process is proposed to progressively
refine the estimation. Both MSE and BER simulations using specifications of the
DTMB system are carried out to prove the effectiveness of the proposed
algorithm even in very harsh channel conditions such as in the single frequency
network (SFN) case
Design of a simulation platform to test next generation of terrestrial DVB
Digital Terrestrial Television Broadcasting (DTTB) is a member of our daily life
routine, and nonetheless, according to new users’ necessities in the fields of
communications and leisure, new challenges are coming up. Moreover, the current Standard is not able to satisfy all the potential requirements.
For that reason, first of all, a review of the current Standard has been performed
within this work. Then, it has been identified the needing of developing a new
version of the standard, ready to support enhanced services, as for example
broadcasting transmissions to moving terminals or High Definition Television
(HDTV) transmissions, among others.
The main objective of this project is the design and development of a physical
layer simulator of the whole DVB-T standard, including both the complete transmission and reception procedures. The simulator has been developed in Matlab. A detailed description of the simulator both from a functional and an architectural point of view is included. The simulator is the base for testing any
possible modifications that may be included into the DVB-T2 future standard. In fact, several proposed enhancements have already been carried out and their performance has been evaluated. Specifically, the use of higher order modulation schemes, and the corresponding modifications in all the system
blocks, have been included and evaluated. Furthermore, the simulator will allow
testing other enhancements as the use of more efficient encoders and
interleavers, MIMO technologies, and so on.
A complete set of numerical results showing the performance of the different parts of the system, are presented in order to validate the correctness of the implementation and to evaluate both the current standard performance and the
proposed enhancements.
This work has been performed within the context of a project called FURIA,
which is a strategic research project funded by the Spanish Ministry of Industry, Tourism and Commerce. A brief description of this project and its consortium
has been also included herein, together with an introduction to the current situation of the DTTB in Spain (called TDT in Spanish)
Design of a simulation platform to test next generation of terrestrial DVB
Digital Terrestrial Television Broadcasting (DTTB) is a member of our daily life
routine, and nonetheless, according to new users’ necessities in the fields of
communications and leisure, new challenges are coming up. Moreover, the current Standard is not able to satisfy all the potential requirements.
For that reason, first of all, a review of the current Standard has been performed
within this work. Then, it has been identified the needing of developing a new
version of the standard, ready to support enhanced services, as for example
broadcasting transmissions to moving terminals or High Definition Television
(HDTV) transmissions, among others.
The main objective of this project is the design and development of a physical
layer simulator of the whole DVB-T standard, including both the complete transmission and reception procedures. The simulator has been developed in Matlab. A detailed description of the simulator both from a functional and an architectural point of view is included. The simulator is the base for testing any
possible modifications that may be included into the DVB-T2 future standard. In fact, several proposed enhancements have already been carried out and their performance has been evaluated. Specifically, the use of higher order modulation schemes, and the corresponding modifications in all the system
blocks, have been included and evaluated. Furthermore, the simulator will allow
testing other enhancements as the use of more efficient encoders and
interleavers, MIMO technologies, and so on.
A complete set of numerical results showing the performance of the different parts of the system, are presented in order to validate the correctness of the implementation and to evaluate both the current standard performance and the
proposed enhancements.
This work has been performed within the context of a project called FURIA,
which is a strategic research project funded by the Spanish Ministry of Industry, Tourism and Commerce. A brief description of this project and its consortium
has been also included herein, together with an introduction to the current situation of the DTTB in Spain (called TDT in Spanish)