WHITEPAPER QNX Acoustics Management Platform · Reinforce speech only and not amplify background noise ... WHITEPAPER QNX Acoustics Management Platform 10 When DSP core performance

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WHITEPAPER

QNX Acoustics Management Platform

Len Layton Product Manager

QNX Software Systems 5/24/16

WHITEPAPER QNX Acoustics Management Platform 1

The QNX Acoustics Management Platform (“AMP”) is an integrated,

holistic, and hardware-independent automotive acoustic signal processing

solution. AMP’s innovative design reduces system cost and complexity,

accelerates time to market, amplifies quality, and performance to

completely new levels.

“Listen, Jim, I heard that Chevy’s rear end. Sounds like bustin’

bottles. Squirt in a couple quarts of sawdust. Put some in the

gears, too.”

-- John Steinbeck, The Grapes of Wrath, 1939.

“Software is eating the world.”

-- Marc Andreessen, Wall Street Journal, 2011.


Introduction

In a hundred years, the sounds that cars make and the ways that automakers have dealt with

those sounds have changed dramatically. New signal processing technologies have

changed the automotive sound experience more than anything, including the innovative

acoustic management platform from QNX, which allows automakers to design the acoustic

experience their customers truly desire.

From the satisfying thunk of a closing door, to the purr of the engine, to the lilt of your favorite singer

on the radio, or the reassuring clack of the seatbelt, the acoustic experience of the automobile is a

critical piece of the interactions that people have with their vehicles.

New ways of looking at (and listening to) a car’s sounds and noises have led QNX’s engineers and

designers to a identify and create a new landscape of design possibilities – with few constraints

from the past.

This whitepaper provides an introduction to the key concepts behind QNX’s new Acoustics

Management Platform (“AMP”) and provides a starting point to understand QNX’s vision to change

the way the industry approaches the holistic automotive acoustic experience.

With a new approach to real-time, low-latency signal processing, and an extensive set of design,

tuning, diagnostic, and analysis tools, QNX AMP delivers a new level of quality, rich features, robust

performance, and standards-compliance to embedded automotive systems while reducing hardware

costs and accelerating development time. AMP combines the following items to a world-class

acoustic experience:

Signal processing on application processors

Complete, integrated acoustics solution

Market-leading features and Performance


The Automotive Acoustic Quartet

Modern vehicles are now shipping with a core set of four acoustic signal processing applications or

functions that each provide basic functionality or improved experience and quality for vehicle

occupants. These form the automotive acoustic quartet:

1. Acoustic Echo Cancellation and Noise Reduction (AECNR) for handsfree telephone calls

2. In-Car Communication (ICC) to improve the audibility of conversations within the car

3. Active Noise Control (ANC) to reduce unwanted engine-related noise 4. Engine Sound Enhancement (ESE) to improve the sound quality of the engine

QNX developed world-leading stand-alone software solutions for each of these functions. These

are outlined in detail below. With QNX AMP all four functions are brought together into an integrated

whole.

Acoustic Echo Cancellation and Noise Reduction (AECNR)

To enable drivers to talk on the phone while driving, it is necessary for the car to have a handsfree

kit installed. Usually, a mobile phone is connected or paired with the car’s audio system via

Bluetooth. However, more recent vehicles may also use newer connectivity approaches for

smartphone handsets such as Apple’s CarPlay or Google’s Android Auto. Essential components of

an automotive handsfree system is the acoustic echo cancellation and noise reduction to ensure

that the far end caller does not hear an echo of their own voice, or hear excessive amounts of

background noise coming from the car. A coordinated set of additional features addresses of all

the remaining noise, gain, and variances that can frustrate a driver.

The Industry Leading Automotive AECNR Solution: QNX Acoustics for Voice 3.1

QNX Acoustics for Voice 3.1 industry leading handsfree telephony experience for cars, and

supports narrow and wide-band Bluetooth, next-generation smartphone telephony and speech

recognition, and call-in concierge voice services at up to 32 kHz sample rates.

Now in its fifth major release, QNX Acoustics for Voice 3.1 builds on the award-winning

performance of previous versions, which have shipped in over 50 million automotive systems from

major OEMs worldwide for over12 years.

QNX Acoustics for Voice 3.1 adds support for the new ITU P.1140 standard for emergency calling

(eCall) in automotive. A feature comparison of the different versions is noted below:


In-Car Communication (ICC)

When travelling at high speed the car can be a noisy

environment – making it hard to have a comfortable

conversation with other occupants. Larger, three-row

SUVs present an even bigger problem as people in the

third row often can’t hear the first row at all when out on

the highway. This situation can become dangerous if the

driver feels they need to twist around and shout to be

heard in the back of the car. In cars that feature a

handsfree phone system there is a microphone that can

pick up the voice of the driver, then can be amplified and

relayed to the speakers in the back. This is the core

principle of QNX In-Car Communication (ICC)

technology.

QNX ICC is the first practical seat-to-seat speech

enhancement software product. It eliminates the need to

twist and shout by enhancing the voice of the driver and

relaying it nearly instantly to the loudspeakers in the

back of the car, just like a public address system. So,

instead of shouting or having to turn around to be heard,

*See glossary on page 15


drivers can talk normally while QNX ICC automatically adapts to the noise conditions in real time

and adds enhancement only when it is needed. Automakers can leverage their existing handsfree

telephony microphones and infotainment loudspeakers to add a feature that consumers will

immediately appreciate.

QNX ICC addresses the whole set of challenges faced when implementing a practical ICC system:

Improved intelligibility by reinforcing speech naturally without distortion or added noise

Automatically adapting the amount of amplification based on the perceptual noise level to avoid any user interaction or distraction

No feedback howling under any circumstances

No unpleasant perceptible effects such as echo

Low delay operation so that reinforced speech does not perceptibly interfere with the direct, non-reinforced speech

Reinforce speech only and not amplify background noise

Simultaneous operation with music and not cause any perceptible distortion to music or other media playback

Implementable on current ICs such as infotainment processor CPUs and DSPs and co-exist with other system software

Tuning that is easy and quickly adapted for different vehicle types and acoustic configurations before production

Active Noise Control (ANC)

Various types of drive-train

technologies, such as variable

cylinder management and lower

RPM torque, help improve fuel

efficiency, but come at the cost

of increased cabin noise.

QNX® Acoustics for Active Noise

Control (“ QNX ANC”) reduces

engine harmonics below 300 Hz

using vehicle RPM data from the

CAN bus and audio data from

cabin microphones. The

software library generates anti-

noise signals (that are equal in

magnitude and opposite in phase to the primary noise)

and emits the signals from the vehicle’s infotainment

loudspeakers, cancelling unwanted engine noise and

improving the experience for drivers and passengers. This

technology is widely deployed in modern cars, but is

expensive to implement with dedicated hardware.


QNX ANC is a pure software solution that runs on the infotainment application processor

under QNX AMP.

QNX ANC has several key advantages over dedicated hardware existing software solutions,

including an extremely small code footprint, built-in rapid calibration, and advanced stability-control

features. QNX ANC’s features and benefits are noted in the table below:

Feature Benefit

Pure software ANC implementation

integrated into QNX Acoustics

Management Platform

Eliminates hardware controller module development

and bill of material costs. QNX AMP provides built-in

audio signal routing and low-latency processing and

mixing.

Built-in calibration software. Rapid, automated in-place calibration of ANC

parameters for each vehicle acoustic platform.

Supported by QNX acoustics

engineers

Worldwide network of automotive software and

acoustics expertise for support, calibration, and tuning

Tuning and diagnostic tool support Includes tools for signal extraction, analysis, and

injection to ensure fast identification of specific noise

issues irrespective of vehicle configuration

Flexible transducer configurations Supports 2 to 6 microphones and 2 to 6 loudspeaker

channels

Up to 5 engine orders and 300 Hz

bandwidth

Addresses all engine-induced low frequency boom

issues


More information on QNX ANC can be found here.

Engine Sound Enhancement (ESE)

Modern cars often have engine sounds that are different from what

buyers expect or that vary over their operating range in unexpected

ways. Many vehicles already incorporate synthetic engine sound

technology that enhances the natural sound of the engine with additional

augmented sounds played over the infotainment loudspeakers.

QNX Engine Sound Enhancement (“ESE”) is a complete automotive

engine sound design and real-time sound synthesis solution. QNX ESE

features two real-time engine sound synthesis technologies: additive

synthesis, and the innovative and unique granular synthesis system that

allows recordings of real vehicles to be dynamically reshaped based on

live engine operating conditions in real-time. QNX ESE includes a

comprehensive engine sound design environment that allows engine

sound profiles to be auditioned along with audio and engine data

recordings right on the designer’s desktop.

QNX ESE Designer

http://www.qnx.com/products/acoustic/anc.html


More information on QNX Acoustics for Engine Sound Enhancement can be found here.

Hazard Warning

Modern vehicles have the potential to have a wide set of acoustic systems running in the cabin

simultaneously. However, these systems can interact with each other in unpredictable ways unless

care is taken at the design stage to make sure each subsystem will be aware of the others.

The following table outlines some of the interaction hazards that can occur between functions such

as handsfree telephony, in-car communications, engine sound enhancement, active noise control,

music and media playback, and automatic speech recognition (“ASR”).

http://www.qnx.com/products/acoustic/ese.html


QNX AMP addresses interaction hazards by ensuring that all reference signals are routed correctly

between functions that need to know about them.

This is a key advantages of QNX AMP: Reference signals are generated and routed to where they

need to go – and is set up correctly by default.

Beautiful Instruments

When the range of acoustic functions were first brought to the car, they required dedicated signal

processing hardware often housed and wired separately from the infotainment system in

independent hardware modules or ECUs (electronic Control Units), which incurred high costs and

significant complexity to connect.

To help address complexity and consolidate the ECUs, semiconductor vendors developed Systems

on a Chip (“SoCs”) that combined multiple special-purpose processing cores into a single device.

Each of these processing cores is designed to perform certain functions in the system. For example,

there might be a general-purpose (“GP”) CPU core or cores designed to run an operating system

and support a graphical display, file system, network interfaces, or other things. There may also be

a dedicated DSP core incorporating hardware to support specific mathematical operations required

to implement functions such as active noise control or equalization filters for loudspeakers. These

DSP cores usually do not have an operating system as they are hardwired to only process specific

signals continuously and in a fixed manner – which also means that they have a very specialized

software development environment that differs markedly from that used for the general-purpose

processor cores under an OS.


When DSP core performance exceeded the GP CPU’s performance for DSP functions it made

sense to divide up the tasks between the cores, despite the architectural complexity this would

induce. For example, there are many situations where signals such as audio need to be passed

back and forth between cores – sometimes multiple times – and manage timing, synchronization,

data formats and other things, which adds significant complexity and makes the whole system more

fragile. However, there were few alternative ways to implement the required functionality. That has

changed.

Today, driven by the demands of smartphones, the raw computing performance of the GP CPU

cores has far outstripped that of the DSP cores on the system, and the GP CPUs have added many

of the signal processing optimizations that were formerly only available in DSPs. For example, many

automotive SoCs feature GP CPU cores that run at over 1 GHz, but the DSP processors remain at

300 MHz or less. This performance gap continues to widen – but many system architectures are still

built around the old divisions of tasks.

Other factors in recent designs are significant restrictions imposed by the operating systems running

on the GP CPUs. Even if you could harness the raw processing performance of these cores, the

OS would not allow real-time, latency-sensitive and demanding signal processing to be delivered

reliably while the system load from applications varied.

Certainly, developing software for GP CPUs under a full operating system, with lots of main memory

is much easier than for DSPs, which would allow system developers to respond much more quickly

to the rapidly evolving requirements coming from the market – if only there was a way to avoid the

software downsides.

The following table compares general-purpose application processors (“Aps”) and digital signal

processor cores from the perspective of the four key acoustic signal processing functions:

handsfree AEC+NR, ICC, ANC, and ESE.


I’m late! I’m late, for a very important date!

One of the most important considerations in the design of an integrated signal processing

architecture is that of latency or delay. This table summarizes the maximum tolerable delay in

milliseconds (thousandths of a second) that each of the functions can bear.

General purpose OSes and CPUs have not been required to implement these functions previously,

even though they easily have enough raw horsepower to do it. The delays induced by the various

buffers and software pieces in the system are one of the biggest reasons.


Introducing LoLLA: A Breakthrough Low Latency Audio Architecture

What if we could have the best of both world: High-performance DSP processing, low-latency audio

processing, robust and reliable co-existence with applications and the rest of the system, together

with the ability to develop software within a modern development environment?

Enter the revolutionary QNX Low-Latency Audio Architecture - “LoLAA” – a new processing

framework that leverages the power of the QNX Neutrino real-time operating system to power a

robust, scalable, low-latency signal processing engine that runs entirely on general purpose

application processor cores.

LoLAA WalksLike a DSP, but Talks Like an Application Processor

LoLAA eliminates the need for dedicated DSP hardware and inter-processor communication.

Latency-sensitive applications such as ICC and ANC can run simultaneously with handsfree

telephony and engine sound enhancement. Latency-tolerant applications can run at their own

individual and preferred rates, while LoLAA seamlessly manages the mixing of inputs and outputs

with the more latency-sensitive functions.

LoLAA extends the existing audio infrastructure in the QNX operating system in a completely

backwards-compatible way so that applications such as telephony, speech recognition, navigation,

and media playback all run entirely unmodified and interact positively with the acoustic signal

processing functions of the system. LoLAA seamlessly manages the synchronous I/O required for

many of these new algorithms, and also provides a single interface for all the supported audio

devices, making latency and synchrony headaches and delays a thing of the past.

The LoLAA system is diagrammed below:


As Marc Andreesen said, ‘software is eating the world’ and nowhere is that more true than in the

car. QNX software already powers the automotive industry’s best infotainment systems and QNX

AMP allows these powerful systems to take over more of the car’s audio and acoustic functionality.

And, there’s much more to come…

Conclusion

Addressing the challenges of the modern automotive system, QNX’s new Acoustics Management

Platform – AMP – takes a holistic approach to managing the acoustic experience for the comfort

and enjoyment of a vehicle’s driver and passengers. QNX AMP is a real time digital signal

processing framework for infotainment application processors that takes on many of the tasks that

were previously assigned to dedicated hardware.

With QNX AMP, automakers have a highly-capable set of tools to manage the sonic experience of

their cars. QNX AMP works with a wide range of system-on-a-chip (SoC) devices that are already

used in automotive designs – saving costs, reducing complexity, and shortening cycle times while


delivering new and incredible sounding features and quality. That sound you hear (or that noise you

don’t) is the future arriving—by car.

Glossary

Term Definition

Acoustic Echo Cancellation (AEC) + High

Efficiency

Advanced high performance echo cancellation at up to 50% less CPU & memory

Adaptive Beam Former & Mixer (CMIX) Adaptive beam-forming and dynamic mixing solution for up to 8 microphones

High Frequency Encoding (HFE) Increases intelligibility by including high-frequency components in narrowband

Dynamic Noise Shaper (DNS) New technology for reducing broadband noise from fans (defrost/HVAC)

Noise Reduction (NR/DNR/LFR) Advanced adaptive noise reduction and low-frequency reconstruction

Wind Block (WB) Eliminates wind buffet noise

Intelligent Voice Optimization (IVO) Advanced automated frequency response correction

Equalization (PEQ/DPEQ) High resolution and Dynam

Auto Gain Control (AGC)/Limiter (LIM) Ensures calls are all heard at same volume and without distortion

Electrical Noise Suppression (ENS) Eliminates electrical noise & interference

Bandwidth Extension (BWE) Improves narrowband voice quality to near-wideband performance

Parametric Equalization (PEQ) Ensures optimum voice quality tuned for specific vehicle configuration

Automatic Gain Control (AGC) Maintains optimum volume level of received voice

Dynamic Level Control (DLC) Dynamically adjusts playback volume based on background noise level

Soft Limiter (LIM) Ensures distortion-free playback over vehicle speakers


QNX Software Systems Limited, subsidiary of BlackBerry is a leading vendor of operating systems, development tools, and professional services for connected embedded systems.

Global leaders such as Audi, Cisco, General Electric, Lockheed Martin, and Siemens depend on QNX technology for vehicle infotainment units, network routers, medical devices, industrial

automation systems, security and defense systems, and other mission- or life-critical applications. Founded in 1980, QNX Software Systems Limited is headquartered in Ottawa,

Canada.

© 2016 QNX Software Systems Limited, All rights reserved. BlackBerry, QNX, QNX CAR, Neutrino, Certicom, and related trademarks, names and logos are the property of BlackBerry

Limited and are registered and/or used in the U.S. and countries around the world.

www.qnx,com

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http://www.qnx,com/

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WHITEPAPER QNX Acoustics Management Platform · Reinforce speech only and not amplify background noise ... WHITEPAPER QNX Acoustics Management Platform 10 When DSP core performance