This paper investigates channel estimation based on training sequences for on-channel repeaters i... more This paper investigates channel estimation based on training sequences for on-channel repeaters in DVB-T/H Single Frequency Networks (SFN). The performance of Maximum Length (MLS) and Constant Amplitude Zero Autocorrelation (CAZAC) Sequences is compared for different channels and different training sequence lengths. CAZAC sequences of shorter lengths outperform MLS sequences for large delay spread channels. Recommendations are given for training sequence type and length and level for DVB-T/H on-channel repeater deployment.
The objective of this paper is to research and develop novel diversity techniques for broadcast t... more The objective of this paper is to research and develop novel diversity techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. Transmitter Diversity will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Rapid development in the area of broadband wireless communications demands wireless multimedia services. One of the challenges of transmitting multimedia over wireless channels is that fading and interference can severely deteriorate the received signals. Orthogonal Frequency Division Multiplexing (OFDM) is a suitable technique for broadband
Abstract—The requirements for future DVB-T/H networks demand that broadcasters design and deploy ... more Abstract—The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is investigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applic...
Abstract—The objective of this paper is to investigate different diversity techniques for broadca... more Abstract—The objective of this paper is to investigate different diversity techniques for broadcast networks that will minimize the complexity and improve received SNR of broadcast systems. Resultant digital broadcast networks would require fewer transmitter sites and thus be more cost-effective and have less environmental impact. The techniques can be applied to DVB-T, DVB-H and DAB systems that use Orthogonal Frequency Division Multplexing (OFDM). These are key radio broadcast network technologies, which are expected to complement emerging technologies such as WiMAX and future 4G networks for delivery of broadband content. Transmitter and receiver diversity technologies can increase the frequency and time selectivity of the resulting channel transfer function at the receiver. Diversity exploits the statistical nature of fading due to multipath and reduces the likelihood of deep fading by providing a diversity of transmission signals. Multiple signals are transmitted in such a way ...
www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast ... more www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. These techniques; Transmitter Diversity and Low Cost On-Channel Repeaters will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Test service scenarios will be developed to illustrate the benefits of the technology so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. Currently in-fill transmitters are used to illuminate “black holes ” where network broadcast signals cannot penetrate. These transmitters generally use different polarisations and frequency channels to the main transmitters. Low cost on-frequency transmitters, although technically demanding could provide a better way of illuminating “black holes ” with minimal complexity and conservin...
www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast ... more www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. These techniques; Transmitter Diversity and Low Cost On-Channel Repeaters will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Test service scenarios will be developed to illustrate the benefits of the technology so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. Currently in-fill transmitters are used to illuminate “black holes ” where network broadcast signals cannot penetrate. These transmitters generally use different polarisations and frequency channels to the main transmitters. Low cost on-frequency transmitters, although technically demanding could provide a better way of illuminating “black holes ” with minimal complexity and conservin...
This paper investigates the design and performance of an FIR echo canceller for on channel repeat... more This paper investigates the design and performance of an FIR echo canceller for on channel repeaters in DVB-T/H network within the framework of the PLUTO project. The possible approaches for echo cancellation are briefly reviewed and the main guidelines for the design of such systems are presented. The main system parameters are discussed. The performance of a FIR echo canceller based on an open loop feedforward approach for channel estimation is tested for different radio channel conditions and for different number of taps of the FIR filter. It is shown that a minimum number of taps is recommended to achieve a certain mean rejection ratio or isolation depending on the type of channel. The expected degradation in performance due to the use of fixed point rather than floating point arithmetic in hardware implementation is presented for different number of bits..
This paper is to investigate the hardware design and implementation of digital echo cancellation ... more This paper is to investigate the hardware design and implementation of digital echo cancellation on-channel repeater (DECOCR) in DVB-T/H networks. There is a need for high isolation between transmitter and receiver antennas for on-channel repeater (OCR) to minimize feedback from the antenna coupling and to keep the system stable. Therefore, the adaptive echo canceller is to remove the echoes between the transmitter and receiver antennas in OCR to minimize the coupling. The design and implementation of DECOCR is based on the algorithm of echo cancellation by channel equalization. The paper will investigate the design and implementation of DECOCR based on digital signal processing (DSP) in FPGA device. The most important issues considered are to get shortest system process delay, highest SNR output and highest echo rejection rate. The laboratory measurement results show that the presented repeater can get up to 29dB echo cancellation and about 1us process delay with robust
This paper presents a test-bed development and measurement plan for evaluating transmit diversity... more This paper presents a test-bed development and measurement plan for evaluating transmit diversity and onchannel repeaters in the Digital Video Broadcasting Network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by enhancing the transmission of signals in NLOS cluttered environments. It is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The on-channel repeater is to extend the coverage of the DVB-T/H network in areas where services are inaccessible by receiving the DVB-T/H signals off air, amplifying and then retransmitting it on the same frequency as received. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems.
An open diversity architecture for a cooperating broadcast wireless network is presented that exp... more An open diversity architecture for a cooperating broadcast wireless network is presented that exploits the strengths of the existing digital broadcast standards. Different diversity techniques for broadcast networks that will minimize the complexity of broadcast systems and improve received SNR of broadcast signals are described. Resulting digital broadcast networks could require fewer transmitter sites and thus be more cost effective with less environmental impact. Transmit diversity is particularly investigated since it obviates the major disadvantage of receive diversity being the difficulty of locating two receive antennas far enough apart in a small mobile device. The schemes examined here are compatible with existing broadcast and cellular telecom standards, and can be incorporated into existing systems without change.
2008 IEEE International Symposium on Consumer Electronics
Transmit diversity is a technique that exploits the nature of fading due to multipaths and that p... more Transmit diversity is a technique that exploits the nature of fading due to multipaths and that potentially incurs delay and pre-and post-echoes into the received signals. There is some concern that early set-top boxes would not be compliant in this respect. Also, introduction of such techniques that would degrade reception for inservice equipments would have an important impact, which should be evaluated. This paper presents a measurement campaign to establish whether the in-service DVB-T receivers are compatible with transmit diversity schemes and also to evaluate the possible diversity loss in the line-of-sight fixed receptions.
2008 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2008
This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantif... more This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial performed during the winter of 2007/2008 in Uxbridge (UK) is described. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive-non line of sight situations.
This paper investigates channel estimation based on training sequences for on-channel repeaters i... more This paper investigates channel estimation based on training sequences for on-channel repeaters in DVB-T/H Single Frequency Networks (SFN). The performance of Maximum Length (MLS) and Constant Amplitude Zero Autocorrelation (CAZAC) Sequences is compared for different channels and different training sequence lengths. CAZAC sequences of shorter lengths outperform MLS sequences for large delay spread channels. Recommendations are given for training sequence type and length and level for DVB-T/H on-channel repeater deployment.
The objective of this paper is to research and develop novel diversity techniques for broadcast t... more The objective of this paper is to research and develop novel diversity techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. Transmitter Diversity will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Rapid development in the area of broadband wireless communications demands wireless multimedia services. One of the challenges of transmitting multimedia over wireless channels is that fading and interference can severely deteriorate the received signals. Orthogonal Frequency Division Multiplexing (OFDM) is a suitable technique for broadband
Abstract—The requirements for future DVB-T/H networks demand that broadcasters design and deploy ... more Abstract—The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is investigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applic...
Abstract—The objective of this paper is to investigate different diversity techniques for broadca... more Abstract—The objective of this paper is to investigate different diversity techniques for broadcast networks that will minimize the complexity and improve received SNR of broadcast systems. Resultant digital broadcast networks would require fewer transmitter sites and thus be more cost-effective and have less environmental impact. The techniques can be applied to DVB-T, DVB-H and DAB systems that use Orthogonal Frequency Division Multplexing (OFDM). These are key radio broadcast network technologies, which are expected to complement emerging technologies such as WiMAX and future 4G networks for delivery of broadband content. Transmitter and receiver diversity technologies can increase the frequency and time selectivity of the resulting channel transfer function at the receiver. Diversity exploits the statistical nature of fading due to multipath and reduces the likelihood of deep fading by providing a diversity of transmission signals. Multiple signals are transmitted in such a way ...
www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast ... more www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. These techniques; Transmitter Diversity and Low Cost On-Channel Repeaters will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Test service scenarios will be developed to illustrate the benefits of the technology so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. Currently in-fill transmitters are used to illuminate “black holes ” where network broadcast signals cannot penetrate. These transmitters generally use different polarisations and frequency channels to the main transmitters. Low cost on-frequency transmitters, although technically demanding could provide a better way of illuminating “black holes ” with minimal complexity and conservin...
www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast ... more www.ist-pluto.org The IST project PLUTO will research and develop novel techniques for broadcast transmitter networks that will minimise the complexity and power consumption of end user equipment. These techniques; Transmitter Diversity and Low Cost On-Channel Repeaters will improve reception in areas of poor coverage such as for mobile reception, indoors and sparsely populated or obscured locations. Test service scenarios will be developed to illustrate the benefits of the technology so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. Currently in-fill transmitters are used to illuminate “black holes ” where network broadcast signals cannot penetrate. These transmitters generally use different polarisations and frequency channels to the main transmitters. Low cost on-frequency transmitters, although technically demanding could provide a better way of illuminating “black holes ” with minimal complexity and conservin...
This paper investigates the design and performance of an FIR echo canceller for on channel repeat... more This paper investigates the design and performance of an FIR echo canceller for on channel repeaters in DVB-T/H network within the framework of the PLUTO project. The possible approaches for echo cancellation are briefly reviewed and the main guidelines for the design of such systems are presented. The main system parameters are discussed. The performance of a FIR echo canceller based on an open loop feedforward approach for channel estimation is tested for different radio channel conditions and for different number of taps of the FIR filter. It is shown that a minimum number of taps is recommended to achieve a certain mean rejection ratio or isolation depending on the type of channel. The expected degradation in performance due to the use of fixed point rather than floating point arithmetic in hardware implementation is presented for different number of bits..
This paper is to investigate the hardware design and implementation of digital echo cancellation ... more This paper is to investigate the hardware design and implementation of digital echo cancellation on-channel repeater (DECOCR) in DVB-T/H networks. There is a need for high isolation between transmitter and receiver antennas for on-channel repeater (OCR) to minimize feedback from the antenna coupling and to keep the system stable. Therefore, the adaptive echo canceller is to remove the echoes between the transmitter and receiver antennas in OCR to minimize the coupling. The design and implementation of DECOCR is based on the algorithm of echo cancellation by channel equalization. The paper will investigate the design and implementation of DECOCR based on digital signal processing (DSP) in FPGA device. The most important issues considered are to get shortest system process delay, highest SNR output and highest echo rejection rate. The laboratory measurement results show that the presented repeater can get up to 29dB echo cancellation and about 1us process delay with robust
This paper presents a test-bed development and measurement plan for evaluating transmit diversity... more This paper presents a test-bed development and measurement plan for evaluating transmit diversity and onchannel repeaters in the Digital Video Broadcasting Network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by enhancing the transmission of signals in NLOS cluttered environments. It is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The on-channel repeater is to extend the coverage of the DVB-T/H network in areas where services are inaccessible by receiving the DVB-T/H signals off air, amplifying and then retransmitting it on the same frequency as received. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems.
An open diversity architecture for a cooperating broadcast wireless network is presented that exp... more An open diversity architecture for a cooperating broadcast wireless network is presented that exploits the strengths of the existing digital broadcast standards. Different diversity techniques for broadcast networks that will minimize the complexity of broadcast systems and improve received SNR of broadcast signals are described. Resulting digital broadcast networks could require fewer transmitter sites and thus be more cost effective with less environmental impact. Transmit diversity is particularly investigated since it obviates the major disadvantage of receive diversity being the difficulty of locating two receive antennas far enough apart in a small mobile device. The schemes examined here are compatible with existing broadcast and cellular telecom standards, and can be incorporated into existing systems without change.
2008 IEEE International Symposium on Consumer Electronics
Transmit diversity is a technique that exploits the nature of fading due to multipaths and that p... more Transmit diversity is a technique that exploits the nature of fading due to multipaths and that potentially incurs delay and pre-and post-echoes into the received signals. There is some concern that early set-top boxes would not be compliant in this respect. Also, introduction of such techniques that would degrade reception for inservice equipments would have an important impact, which should be evaluated. This paper presents a measurement campaign to establish whether the in-service DVB-T receivers are compatible with transmit diversity schemes and also to evaluate the possible diversity loss in the line-of-sight fixed receptions.
2008 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2008
This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantif... more This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial performed during the winter of 2007/2008 in Uxbridge (UK) is described. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive-non line of sight situations.
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Papers by Maurice Bard