Viterbi IP Core User Guide

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ID 683280
Date 11/06/2017
Public
Document Table of Contents
Document Table of Contents x
1. About the Viterbi IP Core 2. Viterbi IP Core Getting Started 3. Viterbi IP Core Functional Description A. Viterbi IP Core User Guide Document Archives 4. Document Revision History
1. About the Viterbi IP Core x
1.1. Intel® DSP IP Core Features 1.2. Viterbi IP Core Features 1.3. DSP IP Core Device Family Support 1.4. DSP IP Core Verification 1.5. Viterbi IP Core Release Information 1.6. Viterbi IP Core Performance and Resource Utilization
2. Viterbi IP Core Getting Started x
2.1. Installing and Licensing Intel® FPGA IP Cores 2.2. IP Catalog and Parameter Editor 2.3. Generating IP Cores ( Intel® Quartus® Prime Pro Edition) 2.4. Simulating Intel® FPGA IP Cores 2.5. DSP Builder for Intel® FPGAs Design Flow
2.1. Installing and Licensing Intel® FPGA IP Cores x
2.1.1. Intel® FPGA IP Evaluation Mode 2.1.2. Viterbi IP Core Intel® FPGA IP Evaluation Mode Timeout Behavior
2.3. Generating IP Cores ( Intel® Quartus® Prime Pro Edition) x
2.3.1. IP Core Generation Output ( Intel® Quartus® Prime Pro Edition)
3. Viterbi IP Core Functional Description x
3.1. Decoder 3.2. Convolutional Encoder 3.3. Trellis Coded Modulation 3.4. Viterbi IP Core Parameters 3.5. Viterbi IP Core Interfaces and Signals
3.3. Trellis Coded Modulation x
3.3.1. Half-Rate Convolutional Codes 3.3.2. Trellis Decoder 3.3.3. About Converting Received Signals 3.3.4. Trellis Termination 3.3.5. Trellis Initialization
3.4. Viterbi IP Core Parameters x
3.4.1. Architecture 3.4.2. Code Sets 3.4.3. Viterbi Parameters 3.4.4. Test Data
3.4.1. Architecture x
3.4.1.1. BER Estimator 3.4.1.2. Node Synchronization
3.4.3. Viterbi Parameters x
3.4.3.1. Soft Symbol Input 3.4.3.2. State Metrics 3.4.3.3. Throughput Calculator 3.4.3.4. Latency Calculator
3.4.4. Test Data x
3.4.4.1. External Puncturing
3.5. Viterbi IP Core Interfaces and Signals x
3.5.1. Avalon-ST Interfaces in DSP IP Cores 3.5.2. Global Signals 3.5.3. Avalon-ST Sink Signals 3.5.4. Avalon Source-ST Signals 3.5.5. Configuration Signals 3.5.6. Status Signals 3.5.7. Viterbi IP Core Timing Diagrams
1. About the Viterbi IP Core
2. Viterbi IP Core Getting Started
3. Viterbi IP Core Functional Description
A. Viterbi IP Core User Guide Document Archives
4. Document Revision History

3.3.1. Half-Rate Convolutional Codes

A 1/2 rate convolutional code encodes one information bit and leaves the second information bit uncoded.
Figure 8. Half-Rate Convolutional Code With an eight-point signal constellation (e.g. eight-PSK), the two bits select one of the four subsets in the signal constellation. The remaining information bit selects one of the two points within each subset.
Figure 9. Mapping of Coded Bits and Sector Numbers

The specific mapping is not important. You can derive other mappings by permutating subsets in a way that preserves the main property of increased minimum distance among the subsets. However, you can create any other mapping, including symbol mappings for 8-PSK, 16-PSK and others.

If you create another mapping, you must correctly connect the branch metrics created outside the IP core to the input ports and correctly configure the polynomials GA and GB for the trellis generation.

Figure 10. Four-State Trellis The four-state trellis is the trellis for the 1/2 rate convolution encoder with the addition of parallel paths in each transition to accommodate the uncoded bit c2. The decoder uses the coded bits (c1, c0) to select one of the four subsets that contain two signal points each It uses the uncoded bit to select one of the two signal points within each subset.
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