参数资料
| 型号： | IP-VITERBI/SS |
| 厂商： | Altera |
| 文件页数： | 5/50页 |
| 文件大小： | 0K |
| 描述： | IP VITERBI LOW-SPEED |
| 标准包装： | 1 |
| 系列： | * |
| 类型： | MegaCore |
| 功能： | Viterbi 低速编译器 |
| 许可证： | 初始许可证 |
第1页第2页第3页第4页当前第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页
1. About This Compiler
This document describes the Altera ? Viterbi Compiler. The Altera Viterbi Compiler
comprises high-performance, soft-decision Viterbi MegaCore functions that
implement a wide range of standard Viterbi decoders.
Viterbi decoding (also known as maximum likelihood decoding or forward dynamic
programming) is the most common way of decoding convolutional codes by using an
asymptotically optimum decoding technique. In its basic form, Viterbi decoding is an
efficient, recursive algorithm that performs an optimal exhaustive search.
A convolutional encoder and Viterbi decoder can be used together to provide error
correction over a noisy channel, e.g., a communications channel. A convolutional
encoder adds redundancy (i.e., extra bits) to a data stream before transmission.
The rate and the generating polynomials describe the convolutional code, hence they
describe the convolutional encoder. The rate is the number of transmitted bits per
input bit, e.g., a rate 1/2 encodes 1 bit and produces 2 bits for transmission. Similarly,
a rate 2/3 encodes 2 bits and produces 3 bits for transmission. A code can be
punctured to increase its rate, by deleting some of the encoded bits according to a
deterministic pattern.
The generating polynomials denote the convolutional encoder state bits, which are
mathematically combined to produce an encoded bit. There is one generating
polynomial per encoded bit. The length in bits of the generating polynomial is called
the constraint length; systems with higher constraint lengths are generally more
robust. However, the complexity of the Viterbi decoder increases exponentially with
the constraint length, so it is unusual to find constraint lengths greater than nine.
A noisy transmission channel causes bit errors at the receiver. The Viterbi algorithm
finds the most likely sequence of bits that is closest to the actual received sequence.
The Viterbi decoder uses the redundancy, which the convolutional encoder imparted,
to decode the bit stream and remove the errors.
The receiver can deliver either hard or soft symbols to the Viterbi decoder. A hard
symbol is equivalent to a binary ±1. A soft symbol is multi-leveled to represent the
confidence in the bit being positive or negative. For instance, if the channel is non-
fading and Gaussian, the output of a matched filter quantized to a given number of
bits is a suitable soft input. Punctured symbols are indicated with the eras_sym input.
The Viterbi algorithm has better performance with soft input symbols.
The Viterbi decoder works on blocks of data, or continuous streams. It takes in N
symbols at a time for processing, where N is the number of encoded symbols. The
traceback length is the number of trellis states processed before the decoder makes a
decision on a bit.
Features
The Viterbi Compiler provides two high-performance, area-optimized, soft-decision
Viterbi decoder MegaCore functions—the hybrid and parallel architecture. For both
MegaCore functions, you can specify the BER estimator, node synchronization, and
multiple code sets (including the variable constraint lengths).
November 2013
Altera Corporation
Viterbi Compiler
User Guide
相关PDF资料 |
PDF描述 |
|---|---|
| IP4220CZ6,125 | IC USB DUAL ESD PROTECT 6TSOP |
| IPA-66-1-600-10.0-A-01-T | CIRC BRKR 10A 2POLE SCREW TERM |
| IPR-CSC | IP COLOR SPACE CONVERTER RENEW |
| IPR-ED8B10B | IP 8B10B ENCODER/DECODER RENEW |
| IPS-VIDEO | IP VIDEO/IMAGE PROCESSING SUITE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| IPW 2819 | 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW 11INX7.5IN 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 11INX7.5IN 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 11INX7.5IN; For Use With:Front Panel Mounted Meters; Enclosure Material:-; IP Rating:(Not Available); Highest NEMA Rating:4X; External Height - Imperial:11"; External Width - Imperial:7.5"; NEMA Type:4X ;RoHS Compliant: Yes |
| IPW 2819-G | 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW 11INX7.5IN 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 11INX7.5IN; For Use With:Front Panel Mounted Meters; Enclosure Material:-; IP Rating:(Not Available); Highest NEMA Rating:4X; External Height - Imperial:11"; External Width - Imperial:7.5"; NEMA Type:4X ;RoHS Compliant: Yes |
| IPW 2828 | 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW 11INX11IN 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 11INX11IN; For Use With:Front Panel Mounted Meters; Enclosure Material:-; IP Rating:(Not Available); Highest NEMA Rating:4X; External Height - Imperial:11"; External Width - Imperial:11"; NEMA Type:4X ;RoHS Compliant: Yes |
| IPW 3819 | 制造商:FIBOX 功能描述:Inspection Window 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 15INX7.5IN, For Use With:Front Panel Mounted Meter 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 15INX7.5IN, For Use With:Front Panel Mounted Meters, Enclosure Material:-, IP Rating:-, NEMA Rating:4X, External Height - Imperial:15", External Width - Imperial:7.5", External Width - Metric:191mm , RoHS Compliant: Yes |
| IPW 3828 | 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW 15INX11IN 制造商:FIBOX 功能描述:INSTRUMENT PROTECTION WINDOW, 15INX11IN; For Use With:Front Panel Mounted Meters; Enclosure Material:-; IP Rating:(Not Available); Highest NEMA Rating:4X; External Height - Imperial:15"; External Width - Imperial:11"; NEMA Type:4X ;RoHS Compliant: Yes |
发布紧急采购，3分钟左右您将得到回复。