Behavior Modeling of a Digital Video Broadcasting System and the Evaluation of its Equalization Methods Master thesis performed in Computer Engineering by Jian Wang, Yan Xie LiTH-ISY-EX--10/4309--SE Linköping 18th March 2010 Behavior Modeling of a Digital Video Broadcasting System and the Evaluation of its Equalization Methods Master thesis performed in Computer Engineering at Linköping Institute of Technology by Jian Wang, Yan Xie LiTH-ISY-EX--10/4309--SE Supervisor: Di Wu, Dake Liu Examiner: Dake Liu Linköping 18th March, 2010 Presentation Date Department and Division Datorteknik 18th March, 2010 Department of Electrical Engineering Publishing Date (Electronic version) Language Type of Publication ISBN (Licentiate thesis) × English Licentiate thesis ISRN: LiTH-ISY-EX--10/4309--SE Other (specify below) × Degree thesis Thesis C-level Title of series (Licentiate thesis) Thesis D-level Report Number of Pages Other (specify below) Series number/ISSN (Licentiate thesis) 82 URL, Electronic Version http://www.ep.liu.se Publication Title Behavior Modeling of a Digital Video Broadcasting System and the Evaluation of its Equalization Methods Author(s) Jian Wang, Yan Xie Abstract In this thesis, a single carrier ATSC DTV baseband transmitter, part of the receiver (including channel estimator and channel equalizer), were modeled. Since multi-path induced ISI (inter symbol interference) is the most significant impact on the performance of single carrier DTV reception, modeling and implementation of single carrier channel estimator and channel equalizer have been the focus of the thesis. We started with the investigation of channel estimation methods. Afterwards, several channel estimators and equalizers were modeled and the performance of each channel equalization methods in different scenarios was evaluated. Our results show that the frequency domain equalizer can achieve low computing cost and handle long delay paths. Another important issue to be considered in block equalization is Inter-Block Interference (IBI). The impact of IBI was investigated via behavior modeling. In last part of our thesis, two methods for IBI cancellation are compared and the proposal for hardware implementation was given. Keywords ATSC, Multipath, Channel Estimation, Channel Equalization, FEQ, Inter-Block Interference Abstract In this thesis, a single carrier ATSC DTV baseband transmitter, part of the receiver (including channel estimator and channel equalizer), were modeled. Since multi-path induced ISI (inter symbol interference) is the most significant impact on the performance of single carrier DTV reception, modeling and implementation of single carrier channel estimator and channel equalizer have been the focus of the thesis. We started with the investigation of channel estimation methods. Afterwards, several channel estimators and equalizers were modeled and the performance of each channel equalization methods in different scenarios was evaluated. Our results show that the frequency domain equalizer can achieve low computing cost and handle long delay paths. Another important issue to be considered in block equalization is Inter-Block Interference (IBI). The impact of IBI was investigated via behavior modeling. In last part of our thesis, two methods for IBI cancellation are compared and the proposal for hardware implementation was given. Acknowledgements Above all, we would like to express our appreciation to Prof. Dake Liu and Dr. Di Wu for introducing us this interesting and challenging topic. Especially, to Prof. Dake Liu for the sharing of his rich experience in industrial field, for his advice on the way of thinking, and also for many valuable discussions we had. We also would like to thank supervisor Di Wu for his help on our system modeling. Apart from this, we would like to deliver our grateful respectively. I would like to thank my parents for always believing in me. Particularly, I would like to thank my girl friend Wei. Thank you for always being there encouraging me when I was going through a tough time mentally and technically during this thesis work. Jian Wang The greatest love to my parents in Lanzhou, China, the love you gave encourages me in the past two and half years. I would not go any further without your patient and support. Yan Xie 22nd, March 2010 Contents 1. Introduction ........................................................................................................... 2 1.1. Background ...................................................................................................... 2 1.2. Objectives ........................................................................................................ 3 1.3. Thesis Guidelines ............................................................................................. 3 2. Digital Television Broadcasting System Overview ............................................. 4 2.1. Introduction ...................................................................................................... 4 2.2. Single carrier VS Multi-carrier ........................................................................ 5 2.3. Digital television broadcast standards family .................................................. 6 3. System Modeling of ATSC-T Standard ............................................................... 8 3.1. System overview .............................................................................................. 8 3.2. Baseband transmission characteristics ............................................................. 9 3.2.1. Overview of block diagram ...................................................................... 9 3.2.2. Data Organization ................................................................................... 10 3.2.3. Block description of channel error protection ........................................ 12 3.2.4. Synchronization ...................................................................................... 16 3.2.5. Modulation .............................................................................................. 18 3.3. VSB terrestrial receiver.................................................................................. 19 3.3.1. Signal processing .................................................................................... 20 3.3.2. Data processing ....................................................................................... 21 4. Wireless Channel ................................................................................................. 23 4.1 Multipath Propagation ................................................................................... 23 4.2 Doppler Effect ................................................................................................ 25 4.3 Channel Types ............................................................................................... 25 4.3.1 Flat fading channel .................................................................................. 26 4.3.2 Frequency selective fading channel ........................................................ 26 4.4 Statistical Channel Models ............................................................................ 27 4.4.1 Rayleigh fading channel ......................................................................... 27 4.4.2 Rician fading channel ............................................................................. 27 4.5 Channel Model used in this thesis ................................................................. 27 5. Channel Estimation ............................................................................................ 29 5.1. Estimation Description................................................................................... 29 5.2. Data aided Estimation Method....................................................................... 30 5.3. Blind Estimation ............................................................................................ 30 5.4. Time Domain Estimation ............................................................................... 30 5.5. Frequency Domain Estimation ...................................................................... 31 6. Channel Equalization ......................................................................................... 33 6.1. Time Domain Equalization ............................................................................ 33 6.1.1. Linear Equalizer ...................................................................................... 34 6.1.2 Nonlinear Equalizer ................................................................................ 41 6.2. Frequency domain equalization ..................................................................... 45 6.2.1. Complexity of TEQ and FEQ ................................................................. 46 6.2.2. Single block FEQ .................................................................................... 46 6.2.3. Consecutive blocks equalization ............................................................. 58 6.2.4. Iterative IBI cancellation......................................................................... 60 7. Mobility and System Budget Analysis............................................................... 67 7.1. Mobility analysis ............................................................................................ 67 7.2. Hardware resource budgets ............................................................................ 68 8. Conclusion