李學智臺灣大學：電信工程學研究所林浩群Lin, Hao-ChunHao-ChunLin2007-11-272018-07-052007-11-272018-07-052005http://ntur.lib.ntu.edu.tw//handle/246246/58729手提式數位無線廣播電視 ( DVB-H ) 是以地面數位無線廣播電視 ( DVB-T )為基礎下，專門為手提式裝置如手機、PDA或Smart Phone等所設計之系統。此二系 統在行動接收方面都會因傳輸通道的快速改變而有所影響。為了能達到較高的移動速度，現有的地面數位無線廣播電視系統都會利用雙接收天線或較複雜之信號處理方式來做為解決方案。但是手提式數位無線廣播電視系統主要是設計給以電 池為電源的小螢幕接收機使用。它必需能達到不管在室內、室外或是行動接收的環境下，都能以單根接收天線來接收各種多媒體服務。 在此論文中，我們利用地面數位無線廣播電視標準中所提供之錯誤修正碼，來改善所接收的信號，以達到更高的移動速度。而新的接收機架構經過最佳化後，可減少硬體複雜度。由模擬的結果可以看出，在以單根接收天線為前提下，能夠達到更高的移動速度和更小的功率需求。.DVB-H ( Digital Video Broadcasting-Handhelds ) dedicated for handhelds is basedon DVB-T ( Digital Video Broadcasting-Terrestrial ). Mobile receptions of both systemsare significantly affected by the fast changing transmission channel. For the purpose ofachieving higher speeds, most of the current solutions for DVB-T propose to use twoantennas at the receiver and a more elaborate signal processing for the channelestimation. But the essential commercial requirements of DVB-H were found to be abattery-powered mobile terminal with a small screen. It should be able to receivemultimedia services using a single antenna in the portable, mobile and indoorenvironments. In this thesis, we exploit the error correction capabilities provided by the channel coding of the DVB-T standard to improve the reliability of the received signals for the purpose of increasing the maximum tolerable doppler frequency. The building blocks of the new structure have been optimized in order to reduce the complexity. Simulations show that the use of the new structure with single antenna yields a better improvement in terms of the maximum tolerable speed and the minimum required SNR.Abstract I Contents III List of Figures VII List of Tables XIII Chapter 1 Introduction …………………………………………………………….1 1.1 Thesis Overview ………………………………………………………………2 Chapter 2 The Overview of DVB-H ……………………………………………….3 2.1 DVB-H Outline ………………………………………………………………..3 2.2 The Comparison with each Transmission Technology ……………………...4 2.3 The Structure of DVB-H ……………………………………………………...6 2.3.1 Link Layer ……………………………………………………………….6 2.3.2 Physical Layer …………………………………………………………...7 2.3.3 The Channel Bandwidth of DVB-H ……………………………………...8 2.3.4 The Comparison between 2k/4k/8k Transmission Mode ………………...9 2.3.5 Hierarchical Modulation and Multiplexing …………………………….10 Chapter 3 The Structure of DVB-H Transmitter in Physical Layer …………...13 3.1 Transport Multiplex Adaptation and Randomization for Energy Dispersal ……………………………………………………….15 3.2 Outer Coder …………………………………………………………………16 3.3 Outer Interleaver ……………………………………………………………17 Contents IV 3.4 Inner Coder ………………………………………………………………….18 3.5 Inner Interleaver …………………………………………………………….20 3.5.1 DEMUX ………………………………………………………………22 3.5.2 Bit Interleaver …………………………………………………………22 3.5.3 Symbol Interleaver ……………………………………………………23 3.5.4 In-depth Symbol Interleaver …………………………………………..25 3.6 Signal Constellation and Mapping …………………………………………26 3.7 OFDM Modulation ………………………………………………………….30 3.7.1 OFDM Modulator ……………………………………………………..30 3.7.2 Guard Interval and Cyclic Prefix ……………………………………...32 3.7.3 OFDM Frame Structure ……………………………………………….33 3.8 The Reference Signal ………………………………………………………..37 3.8.1 Positions of the Continual Pilot Carriers ……………………………...38 3.8.2 Positions of the Scatter Pilot Carriers …………………………………40 3.8.3 TPS ( Transmission Parameter Signaling ) ……………………………43 Chapter 4 The Structure of DVB-H Receiver in Physical Layer ……………….47 4.1 A New Structure to Improve the Performance of the Receiver …………..47 4.2 Channel Estimation …………………………………………………………50 4.2.1 Scatter Pilot Extraction ………………………………………………..51 4.2.2 Time Domain Interpolation …………………………………………...52 4.2.3 Frequency Domain Interpolation ……………………………………..53 4.3 FEQ ( Frequency Equalizer ) ………………………………………………54 4.4 Demapper ……………………………………………………………………55 4.5 Inner Deinterleaver …………………………………………………………57 4.6 Viterbi Decoder ……………………………………………………………...58 Contents V 4.7 Convolutional Deinterleaver ……………………………………………….59 4.8 Reed-Solomon Decoder …………………………………………………….59 Chapter 5 Simulation Results and Comparison ………………………………...63 5.1 Channel Model ………………………………………………………………63 5.2 The Simulation Results in the Static Channel Model ……………………..66 5.2.1 The Comparison between Modes of CodeRate and Methods of Equalization ……………………………………………….66 5.2.2 The Comparison between Signal Constellations and Methods of Equalization ……………………………………………….68 5.2.3 The Comparison between Signal Constellations and Modes of Code Rate …………………………………………………...69 5.2.4 The Comparison between Channel Models …………………………...71 5.3 The Simulation Results in the Mobile Channel Model ……………………72 5.3.1 The Comparison between Methods of Equalization and Doppler Frequency in Different Channel Models ……………………..73 5.3.2 The Comparison between Interleavers and the FFT Modes of the OFDM Modulation in the TU6 Channel Model ………………..78 5.3.3 The Comparison of the Maximum Tolerable Doppler frequency in the TU6 Channel Model …………………………………………...81 Chapter 6 Conclusion ……………………………………………………………..85 Reference ……………………………………………………………………………...892013649 bytesapplication/pdfen-US手提式數位無線廣播電視正交分頻多工DVB-HDVB-TOFDMMPE-FECQEFQEFIP2dthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/58729/1/ntu-94-R92942044-1.pdf