Section 1 Introduction; General Information - Digital Voice Systems VC-55-PR User Manual

VC-55™ PR Voice Codec Board
(Preliminary)
User's Manual
Introduction

General Information

The Digital Voice Systems, Inc. (DVSI) VC-55™- PR Vocoder Board is a single channel full-duplex real-
time voice processing board. The VC-55™-PR Vocoder Board implements DVSI's proprietary Advanced
Multi-Band Excitation™ voice coding algorithm software.
The VC-55™- PR Vocoder Board is a full-duplex real-time voice compression solution that is ideally
suited for OEM systems in a variety of applications including digital mobile radio communication
systems, wireless telephony and voice monitoring / recording systems compressed-voice storage ideal
for or non-real-time testing and evaluation of DVSI vocoder performance applications. With its single
channel capability and compact design the PC board is engineered for easy integration into a new or
existing digital communication systems.
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The VC-55™- PR hardware incorporates DVSI's patented voice compression vocoder software geared
toward the next generation of APCO Project 25 (P25) digital mobile radio communication systems.
Providing the best in voice compression performance, the VC-55™- PR integrates an enhanced dual
rate (7200/3600 bps) APCO P25 implementation.
The enhanced full-rate 4400 bps vocoder with 2800 bps of integrated Forward Error Correction (FEC)
significantly improves voice performance and provides a number of other vocoder advancements while
remaining fully interoperable with the existing APCO Project 25 vocoder standard (TIA-102BABA). The
enhanced half-rate APCO P25 vocoder operates at 2450 bps with 1150 bps of FEC to maximize system
resources and improve channel efficiency by doubling the number of public safety communication
channels. This low-bit-rate vocoder is fully interoperable with the new half-rate vocoder proposed by
DVSI for APCO Project 25 Phase II.
Both vocoders are based on DVSI's Multi-Band Excitation (MBE) technology that codes speech using a
set of MBE model parameters for each frame of speech. These enhanced vocoders advance this
speech coding method even further. By incorporating DVSI's latest quantization, Forward error
Correction (FEC) and Noise suppression technology they maximize communication system resources
and improve user comprehension (even in channel conditions degraded by significant bit errors or
acoustic background noise). In recent MOS testing, DVSI's enhanced low bit rate vocoders have been
proven to consistently score significantly above the competition by delivering the highest quality voice
DVSI Confidential Proprietary
VC-55™- PR Features
DVSI AMBE™ +2 Voice Coder provides Superior
Voice Quality
Robust to Bit Errors & Background Noise
Dual Data Rates - 7.2 kbps and 3.6 kbps
Real-Time Full-Duplex Communication
High performance audio using 16-bit linear stereo
codec.
Compact Design
Low Power Consumption
Low Cost
USB port provides system setup and control.
The embedded system software is field upgradeable.
Windows 98 Win2K and WinXP Compatible
Section 1 – Introduction
Digital Voice Systems, Inc.
The Speech Compression Specialists
Page 1