Table of Contents
Advertisement
Table of Contents
CHAPTER 5. THEORY OF OPERATION ...................................................................5-1
5.1 Modulator ......................................................................................................................................................... 5-1
5.1.1 General description..................................................................................................................................... 5-1
5.1.2 Specifications.............................................................................................................................................. 5-1
5.1.3 Theory of Operation ................................................................................................................................... 5-6
5.2 Viterbi Decoder / Demodulator Processor ..................................................................................................... 5-7
5.2.1 General Description .................................................................................................................................... 5-7
5.2.2 Viterbi Decoder/Demod Processor Specification ....................................................................................... 5-7
5.2.2.1 Demod Processor Specification........................................................................................................... 5-7
5.2.2.2 Viterbi Decoder Specifications............................................................................................................ 5-8
5.2.3 Theory Of Operation................................................................................................................................. 5-14
5.2.3.1 Demod Processor............................................................................................................................... 5-14
5.2.3.2 Viterbi Decoder ................................................................................................................................. 5-14
5.3 Demodulator................................................................................................................................................... 5-15
5.3.1 General Description .................................................................................................................................. 5-15
5.3.2 Specifications............................................................................................................................................ 5-16
5.3.3 Theory of Operation ................................................................................................................................. 5-19
5.4 Reacquisition, Fast Acquisition And Directed Sweep ................................................................................. 5-19
5.4.1 General ..................................................................................................................................................... 5-19
5.4.2 Reacquisition ............................................................................................................................................ 5-20
5.4.3 Fast Acquisition ........................................................................................................................................ 5-21
5.4.4 Directed Sweep......................................................................................................................................... 5-21
CHAPTER 6. MAINTENANCE....................................................................................6-1
6.1 System Checkout .............................................................................................................................................. 6-1
6.1.1 General ....................................................................................................................................................... 6-1
6.1.2 Modulator Checkout ................................................................................................................................... 6-1
6.1.3 Demodulator Checkout ............................................................................................................................... 6-1
6.1.4 Test Points .................................................................................................................................................. 6-8
6.1.4.1 Modulator (Figure 6-5)........................................................................................................................ 6-8
6.1.4.2 Demodulator (Figure 6-6).................................................................................................................... 6-9
6.1.4.3 Viterbi Decoder/demod Card AS/0701 (Figure 6-7) ......................................................................... 6-10
6.1.4.4 Viterbi Decoder/Demod Card AS/0949 (Figure 6-8) ....................................................................... 6-11
6.1.4.5 Viterbi Decoder/Demod Card AS/2133 (Figure 6-9) ....................................................................... 6-12
6.2 Fault Isolation................................................................................................................................................. 6-13
6.2.1 Modulator Faults....................................................................................................................................... 6-13
6.2.2 Demodulator Faults .................................................................................................................................. 6-14
6.2.3 Common Equipment Faults ...................................................................................................................... 6-15
6.3 Interface Fault Isolation ................................................................................................................................ 6-15
6.3.1 Transmit Overhead Framing Unit Faults .................................................................................................. 6-16
6.3.2 Receive Overhead Framing Unit Faults.................................................................................................... 6-16
6.4 Module Replacement ..................................................................................................................................... 6-22
6.5 Module Identification .................................................................................................................................... 6-22
viii
SDM-309B Satellite Modem
Rev. 0
Advertisement
Table of Contents
