ARINC 741-3 : 1994

5.0 VOICE ENCODER STANDARDS
5.1 Introduction
5.2 General Introduction to Multipulse-
                        Excited LPC
5.2.1 LPC Synthesis
5.2.2 Multipulse-Excited LPC
5.2.3 Multipulse-Excited LPC Encoder
5.2.4 Multipulse-Excited LPC Decoder
5.3 Multipulse-Excited LPC Encoding
5.3.1 Introduction
5.3.1.1 Encoder Framing Structure
5.3.1.2 High-Level Language Conventions
5.3.1.3 Requirements for Numeric Calculations
5.3.1.4 Audio Input Characteristics
5.3.1.4.1 Audio Input Spectral Characteristics
5.3.1.4.2 Sampling, Quantization, and Scaling
5.3.2 The Encoding Process
5.3.3 LPC Analysis
5.3.3.1 Segmentation and Windowing
5.3.3.2 Autocorrelation
5.3.3.3 Durbin's Recursion
5.3.3.4 Quantization of the Partial Correlation
                        Coefficients
5.3.3.5 Step Up Procedure
5.3.4 Long Term Correlation Analysis
5.3.4.1 Inverse Filtering
5.3.4.2 Long Term Correlation Process
5.3.4.3 Quantization of Long Term Correlation
                        Gain
5.3.4.4 Line Codes Allocated to the Long Term
                        Correlation Delay Parameter
5.3.5 The Local Decoder
5.3.5.1 The Excitation Generator
5.3.5.2 The Long Term Predictor
5.3.5.3 The Short Term Predictor
5.3.6 Excitation Analysis
5.3.6.1 Derivation of the Error Signal
5.3.6.2 Impulse Response Calculations
5.3.6.3 Cross-Correlation Calculation
5.3.6.4 Pulse Selection Procedure
5.3.6.5 Pulse Amplitude Quantization
5.3.6.6 Pulse Amplitude Normalization
5.3.6.7 Pulse Position Encoding
5.4 Parameter Transmission
5.4.1 Introduction
5.4.2 Error Protection
5.4.2.1 Single Bit Error Correction and Double
                        Error Detection
5.4.2.2 Burst Error Detection
5.4.3 Transmission Frame Structure
5.5 The Decoder
5.5.1 Introduction
5.5.2 Decoding of the Partial Correlation
                        Coefficients
5.5.3 Long Term Predicator Parameter Decoding
5.5.4 Excitation Parameter Decoding
5.5.4.1 Pulse Positions
5.5.4.2 Pulse Amplitudes
5.5.5 Operation of the Decoder
5.5.5.1 The Muting Process
5.5.5.2 Speech Output Transcoding
6.0 DATA INTERFACE UNIT FUNCTIONAL
                        REQUIREMENTS
6.1 General
6.2 Plesiochronous Interconnection
                        Requirements
6.3 Rate Adaption Scheme
7.0 TERMINAL INTERFACE FUNCTIONAL UNIT (TIFU)
ATTACHMENT 3X
6 The Terminal Interface Function (TIF)
7 TIF Functional Requirements
8 TIF Operation
9 TIF Interface Requirements
10 Power Control for Higher-Quality Channels
11 Summary of Voice and TIF Encoder/Decoder
                        Transmission Delays and Timings
12 Applicable Documents
                        Glossary
ATTACHMENT 3X TABLES
12 Performance of the TIF Error Protection/
                        Correction Schemes for User Data
13 Rate Adaption Summary
14 300 bit/s User Data Rate (V.21)
15 600 bit/s User Data Rate (V.22)
16 1.2 kbit/s User Data Rate (V.22/V.22bis)
17 2.4 kbit/s User Data Rate
                        (V.22bis/V.27ter)
18 4.8 kbit/s User Data Rate (V.27ter)
19 7.2 kbit/s User Data Rate (V.29)
20 9.6k bit/s User Data Rate (V.29)
21 31 bit Signalling Control Codes
22 Plesiochronous Buffer Codes
23 BursT Error Detection Bits
24 TIF Transmission Frame Structure
                        300 bit/s User Data-Rate
25 TIF Transmission Frame Structure
                        600 bit/s User Data-Rate
26 TIF Transmission Frame Structure
                        1.2kbit/s User Data-Rate
27 TIF Transmission Frame Structure
                        2.4kbit/s User Data-Rate
28 TIF Transmission Frame Structure
                        4.8kbit/s User Data-Rate
29 TIF Transmission Frame Structure
                        7.2kbit/s User Data-Rate
30 TIF Transmission Frame Structure
                        9.6kbit/s User Data-Rate (preamble frame)
31 TIF Transmission Frame Structure
                        9.6kbit/s User Data-Rate (data frame)
32 TIF Transmission Frame Structure
                        9.6kbit/s User Data-Rate (postamble frame)
ATTACHMENT 3X FIGURES
11 Simplified Functional Block Diagram of
                        TIF Encoder
12 Simplified Functional Block Diagram of
                        TIF Decoder
13 Simplified TIF Encoder Operation
                        Flowchart
14 Simplified TIF Decoder Decision Logic
                        (Error Burst Detection/Codec Muting
                        Strategy)