Digital Video Broadcasting Signal Research Articles

Direct-Link Interference Cancellation Design for Backscatter Communications Over Ambient DVB Signals

Ambient backscatter (AB) communication enables the backscatter devices to modulate and transmit data by reflecting surrounding digital video broadcasting (DVB) signals, and has emerged as a promising solution to connect low-power and small-sized devices in Internet of Things (IoT). Unfortunately, the AB receiver may suffer from the strong direct-link interference (DLI) transmitted from the ambient DVB station, making it difficult to decode the backscattered signal (BS) directly. In this paper, to tackle this issue, we propose a DLI cancellation method for AB communications over ambient DVB signals. First, a general signal processing operation for DLI cancellation at the AB receiver is designed, where neither special design on waveform nor cooperation between the ambient DVB station and the backscatter transceiver is required. Then, by minimizing the residual reception power after DLI cancellation, a three-layer parameter searching algorithm is proposed to separate the BS from the ambient DVB signal, which is of low implementation complexity. Simulation results show that when the DLI-to-BS ratio (ISR) is greater than 30 dB, the proposed DLI cancellation method can effectively suppress the DLI at the AB receiver, and the demodulation and capacity performance of the ambient DVB transmission and the backscatter transmission are barely deteriorated, as compared with the scenarios of original DVB transmission without BS and pure backscatter transmission without DLI. In addition, there is a trade-off between the convergence time and the interference cancellation ratio (ICR) performance of the proposed DLI cancellation scheme.

Spectral Overlap Optimization for DVB-T2 and LTE Coexistence

In this paper, we analyze the spectral coexistence between the second generation terrestrial digital video broadcasting (DVB) and the long term evolution (LTE) networks. In particular, the global spectral efficiency (SE) of both systems is investigated when a partial spectral overlap between DVB and LTE signals occurs. Our contribution lies in twofold: 1) the interfering signal variance in each network is derived analytically according to the frequency overlap while taking into account the difference between the characteristics of LTE and DVB networks, especially the OFDM subcarrier spacing and then the OFDM symbol duration and 2) SE is derived with uniform and non uniform power allocation between overlapped and non overlapped subcarriers of the two networks. This derivation offers an analytical evaluation of the effect of the spectral overlap ratio variation and different power allocation scenarios and provides insightful results on the cooperation between the two networks.

Wavelet transformation method to allocate the DVB-T signals peaks

Terrestrial digital video broadcasting (DVB-T) is considered as one of the main two popular broadcasting standards, which facilitates the transmission of digital television in handheld receivers. In this work, a comparison will be held on the physical layer level in order to enhance the wireless systems' performance. It is attained by exploiting a recently published work that is based on the wavelets entropy and a new proposition that is based on a special averaging technique. Those two propositions have been used to tackle the peak-to-average power ratio (PAPR) problem that is found in the used orthogonal frequency division multiplexing (OFDM) technique. This comparison asset from BER curves and CCDF curves in order to distinguish between them. A MATLAB simulation has been run in order to validate the numerical achieved results of the proposed work. At the same bandwidth occupancy of the speaker verification-based systems, the proposed technique shows additional enhancement in both of CCDF and BER curves...

Wavelet transformation method to allocate the DVB-T signals peaks

Terrestrial digital video broadcasting (DVB-T) is considered as one of the main two popular broadcasting standards, which facilitates the transmission of digital television in handheld receivers. In this work, a comparison will be held on the physical layer level in order to enhance the wireless systems' performance. It is attained by exploiting a recently published work that is based on the wavelets entropy and a new proposition that is based on a special averaging technique. Those two propositions have been used to tackle the peak-to-average power ratio (PAPR) problem that is found in the used orthogonal frequency division multiplexing (OFDM) technique. This comparison asset from BER curves and CCDF curves in order to distinguish between them. A MATLAB simulation has been run in order to validate the numerical achieved results of the proposed work. At the same bandwidth occupancy of the speaker verification-based systems, the proposed technique shows additional enhancement in both of CCDF and BER curves. Moreover, it reduces the previously added complexity to the structure in the receiver side. An extra 25% reduction is achieved in the essence of PAPR and around 35% extra noise immunity.

A 280 W LDMOS broadband Doherty PA with 52% of fractional bandwidth based on a multi-line impedance inverter for DVB-T applications

We introduce a new technique for the design of an output combiner for Doherty power amplifier (DPA) and its effective exploitation for the development of a wideband laterally diffused metal oxide semiconductor (LDMOS) DPA. The design is enabled by a two-line impedance inverter for the DPA back-off operation, which is capable of 52% of fractional bandwidth. The technique is validated by the development of a DPA prototype for Ultra high frequency terrestrial digital video broadcast (DVB-T) applications, with optimized peak power and efficiency over 470–806 MHz. The prototype delivers between 40 and 53% of average efficiency across the band, at 49 dBm output power in average across the bandwidth, and supporting DVB-T signals with 8 MHz bandwidth and a peak-to-average power ratio of 10.5 dB. It achieves the target adjacent channel power ratio of −52 dBc at 750 MHz if digital pre-distortion is applied, and provides 47.8 dBm of output power with a drain efficiency of 44.3%.

Design of multi-band CPW-fed antenna for triple-frequency operation

Presented is a coplanar waveguide fed antenna for multi-band operation covering the digital video broadcasting signal reception in the UHF band, mobile communications in the GSM band, and the 2.4 GHz 802.11g/n band. The size of the designed antenna is 114×60 mm and it is printed on an FR4 substrate of thickness 0.8 mm with dielectric constant 4.4. It has an inner U-shaped strip enclosed by an outer loop strip and the outer loop strip is designed to obtain a wide operating bandwidth. Experimental results show that the proposed antenna exhibits a good impedance matching over a wide frequency range of 470 to 960 MHz, 1450 to 1880 MHz, and 2.4 to 2.6 GHz.

Compact Multiband Multifolded-Slot Antenna Loaded With Printed-IFA

Compact multiband coplanar waveguide-fed L-loaded printed-inverted-F antennas (printed-IFAs) with multiple-folded-slots (MFS) transmission line is proposed in this letter. The proposed antenna is designed for the transmission and reception of the digital video broadcasting signal DVB (470-860 MHz) frequency band and DVB-L (1452-1492 MHz) band. The proposed antenna is suitable for use in the global system for mobile communication (GSM 850/900), all bands of long term evolution (LTE), covering from 800 MHz to 2.6 GHz, industrial, scientific and medical (ISM) 2.45 GHz, Wi-Max bands at 3.5 GHz and 5.7 GHz, WLAN 5.2 GHz and other wireless communication applications. Multiband behavior is achieved by loading folded slots CPW-fed with L-loaded printed-IFA. Capacitive loads are added at the open end of the L-loaded printed-IFA for additional reduction of the antenna size. The proposed antenna possesses the properties of good performance, compact size, low profile, and low cost. Hence, it is suitable for implementation in wireless applications.

Power Measurement in DVB-T Systems: On the Suitability of Parametric Spectral Estimation in DSP-Based Meters

Performance assessment and large-scale monitoring of terrestrial digital video broadcasting (DVB-T) transmission apparatuses are currently a pressing need due to the rapid growth of related broadcasting networks in many countries. Power measurements, in particular, play a very important role since RF and IF signal power, RF channel power, RF and IF power spectrum, noise (or unwanted) power, and power efficiency are relevant parameters to be measured as accurately as possible. Although modern spectrum analyzers and high-performance vector signal analyzers exhibit satisfying accuracy and repeatability, their cost, weight, and size make them unsuitable for the purpose. This paper is focused on the design and realization of a digital signal processing-based meter for power measurement in DVB-T systems that is capable of granting good accuracy, satisfying repeatability, reduced measurement time, and cost effectiveness. This paper deals with the digital signal processing algorithm to be implemented in the meter, paying attention to parametric power spectral density (PSD) estimators for their reduced memory requirement and potentially limited computational burden. In particular, a parametric estimation algorithm that is capable of assuring a fast measurement rate is implemented and made operative. The simulation and emulation stages are properly designed to regulate the most relevant parameters of the adopted PSD estimators according to the specific features of the signals involved; a number of experiments on actual DVB-T signals are conducted, the results of which are compared to those provided by competitive measurement solutions.