Denoiser DSP Board · 2013-11-24 · Denoiser DSP Board STC-H209 Denoiser DSP board is designed as one-channel board for noise reduction. Denoiser DSP provides noise-cancellation

Denoiser DSP Board

Technical DescriptionOperating Instructions

Speech Technology CenterSt.-Petersburg, Russia2003

Contents

Necessary Information. . . . . . . . . . . . . . . . . . . . . 7Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1 Denoiser DSP Board 9STC-H209 Technical Specification. . . . . . . . . . . . . . . 10Optional improvements. . . . . . . . . . . . . . . . . . . . . 12Connector Configuration. . . . . . . . . . . . . . . . . . . . 13

2 Denoiser Set 17

3 Denoiser Development Kit 19Assembling Denoiser Development Kit. . . . . . . . . . . . 20

System requirements. . . . . . . . . . . . . . . . . . . 20Preparing Denoiser Development Kit for operation. . . 20

Tuning Denoiser DSP broadband filtering. . . . . . . . . . . 23Noise reduction settings. . . . . . . . . . . . . . . . . . 24Hardware settings. . . . . . . . . . . . . . . . . . . . . 24Sound processing. . . . . . . . . . . . . . . . . . . . . 25Signal input and output cables. . . . . . . . . . . . . . 26

Stereo noise-cancellation. . . . . . . . . . . . . . . . . . . . 28

4 Delivery Set 31Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

5

6 CONTENTS

Tested and Approved. . . . . . . . . . . . . . . . . . . . . . 32Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

A Set of cables for DDK mono 33

NECESSARY INFORMATION 7

Necessary Information

Listed below are the telephone numbers that you may need if any ques-tions or problems regarding the operation of Speech Technology Centerproducts arise:

Tel: +7 (812) 331-0665Fax: +7 (812) 327-9297Mail: Russia, 196084, Saint-Petersburg, P.O. Box 452Office: 4 Krasutskogo str., Saint-PetersburgE-mail: [email protected]: http://www.speechpro.com

When requesting assistance, you should have the following infor-mation readily available:

• name of the product and version number

• type of the computer and information about its configuration

• name of OS being used and its version number

• precise description of the problem.

Overview

Denoiser DSP Board (STC-H209) designed by Speech Technology Cen-ter Limited (STC Ltd.) provides a complex noise-cancellation solution.It may be delivered in one of the three basic configurations listed in thetable below.

8 CONTENTS

Denoiser DSP Denoiser Set DenoiserBoard Development Kit

STC-H209 DSP board + + +

STC-H210 I/O board - + +

STC-H230 board - - +

Altera ByteBlaster - - Optional

Power Supply Unit - - +

External Control Unit - - +

Sound I/O cables - - +

Power Supply Adapter - - Optional

STC-S209 software - - +

Operating instructions + + +

Denoiser DSP Boardsupposes, that only STC-H209 Denoiser DSPboard with embedded noise-cancellation algorithms is supplied. All thetechnical data on this board are provided inchapter 1of this manual.

Denoiser Setincludes STC-H210 sound I/O board in addition toSTC-H209. This board facilitates embedding of Denoiser DSP intocustomer’s applications. So, if you have purchasedDenoiser Setyoushould also pay attention tochapter 2of the manual, where STC-H210board is described.

Denoiser Development Kitis the most full type of available ship-ment versions. It includes STC-H209 and STC-H210 as well as STC-H230 interface board, full set of audio cables, power supply unit andother necessary equipment. Consultchapter 3 for details onDenoiserDevelopment Kit.

Note, that you may always contact STC to order any additional itemslisted there.

Chapter 1

Denoiser DSP Board

STC-H209 Denoiser DSP board is designed as one-channel board fornoise reduction. Denoiser DSP provides noise-cancellation in real-timemode and keeps useful signal clear and undistorted. It is the kernel ofthe whole Denoiser DSP system.

Figure 1.1: Denoiser DSP board

Denoiser DSP effectively filters out the noise, generated by air con-ditioners, street traffic, wind; power supply hum; engine rumbling; chan-

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10 CHAPTER 1. DENOISER DSP BOARD

nel interferences; atmospheric noises etc, as a result signal quality andspeech intelligibility are greatly increased.

Features of Denoiser DSP allow to use it for such applications as:

Telecommunication – phones, mobiles, hands free kits, headsets, andothers.

Aircraft communication – speech of aircraft pilots and dispatchers be-comes more intelligible that leads to more safety.

Dictation devices and voice logging systems– time of speech transcrib-ing decreases (up to 2 times).

ASR systems– performance of the most known ASR engines increases.

STC-H209 Technical Specification

STC-H209 is double-sided PCB board, 51,94×40,64×6 mm with anexternal I/O connector. Backside of the board with all the necessarysizes and attachment points is shown on Fig.1.2.

The board is outfitted with:

• TMS320VC5402PGE DSP byTI for real-time processing, work-ing at 100 MHz max; DSP processor allows for using real-timenoise reduction algorithms.

• KXO-V97-10MHz Generator;

• TLV320AIC23 Stereo Codec byTI ;

• HOP-22A-1190-TF Input/output connector byJST.

STC-H209 board specification is listed in the table below.

STC-H209 TECHNICAL SPECIFICATION 11

Figure 1.2: STC-H209 board sizes

Supply voltage +5 VConsumption current ≤ 90 mALoad resistance up to 32Ω (headphones)Nominal output capacity at40Ω

30 mw

Nominal input signal level(Vp-p for microphone input)

0,004

SNR for microphone input(at least)

72 dB

THD for microphone inputnot more, than

0,05 %

Effective frequency range(at least)

300-3400 Hz

Crosstalk attenuation for mi-crophone input (at least)

80 dB


Analog input channel may be connected to:

• electret microphone;

• dynamic microphone;

• line output of external audio equipment (optional).

Important!We recommend that you use KNOWLES EK 3024 microphonesto ensure proper function of Denoiser DSP.

Optional improvements

In addition to standard board layout certain optional modifications listedin table below may be made.

Item Standard Optional

Inputs microphone linearOutputs 32Ω (headphones) linearN of channels 1 2Sampling rate 8 kHz 1×16 or 2×8 kHz∗

External control unit Bypass/Denoiser switch External connector∗ For two linear inputs

Note, that all the specifications provided in this manual are validfor standard Denoiser DSP configuration. For technical data on op-tional improvements, please, contact STC as specified inNecessaryInformation .

CONNECTOR CONFIGURATION 13

Connector Configuration

Denoiser DSP performs signal input and output via board-to-boardHOconnectorby JST, model No.HOP-22A-1190-TFinstalled on the back-side of the board (X2 onFigure 1.2). Fig. 1.3. shows this connector andall its necessary sizes.

Figure 1.3: HO connector overview

HO connector specification is listed in the table below.

Current rating 1.0A AC, DCVoltage rating 250V AC, DCTemperature range −20C to+85C (including

temperature rise in applyingelectrical current)

Contact resistance Initial value – 30mΩ max.After environmental testing– 50mΩ max.

Insulation resistance 1.000 MΩ min.Withstanding voltage 500V AC/minute

∗ – ContactJST for details


HO connector is mounted on Denoiser DSP board and does not needthe mating connector. I.e. the mating part is to be implemented as SMDpadstacks’ footprint. This footprint should be mounted on the card, towhich the Denoiser DSP board is connected as shown onFigure 1.4be-low. Note, that footprint’s position is strictly determined by the locationof the connector on STC-H209 relative to the board mounting holes (seeFigure 1.2).

Figure 1.4: Mating footprint for HOP connector

CONNECTOR CONFIGURATION 15

Specification of the connector pins is provided in the table below

Contact Circuit Name Description1 Ground Ground2 +5 V POWER3 Reserved4 +5 V POWER5 Reserved6 +5 V POWER7 Ground Ground8 +5 V POWER9 Reserved10 Reserved11 In LIN or Microphone12 Out LIN or 30 mW into 32 Ohm

from a 3.3 V analog supply volt-age

13 SCLKR *14 FSX *15 FSR *16 SCLKX *17 DR Input pin. Algorithm on – 0 V;

Algorithm off – 3.3 V18 DX *19 RxD *20 TxD *21 mic IN GND Microphone ground22 /INT0 *∗ – According to the data sheet on TMS320VC5402DSP processor byTexas Instruments

Chapter 2

Denoiser Set

Denoiser Set includes additional STC-H210 expansion board providedwith STC-H209. This expansion board facilitates testing and embed-ding of Denoiser DSP board into customer’s applications. It is outfittedwith sound input/output 2.5 mm jack sockets, 5V power supply socketand expansion connector. STC-H210 sizes are 53,77×51,05×8 mm.Figure 2.1displays STC-H209 board properly connected and mountedon STC-H210.

STC-H209 is mounted on STC-H210 expansion board and connectedto it with HO connector described in the previous chapter. OnFigure 2.2you can see STC-H210 board layout with all the external connectorsspecified.

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18 CHAPTER 2. DENOISER SET

Figure 2.1: Denoiser Set

Figure 2.2: STC-H210 connectors’ layout

Chapter 3

Denoiser Development Kit

Denoiser Development Kit (DDK)is the most full shipment of DenoiserDSP product. It provides you with a possibility to adjust board process-ing parameters via PC. In addition to Denoiser DSP board and STC-H210 interface board the kit includes:

• STC-H230 upgrade board;

• Denoiser DSP board adjustment software CD;

• Set of signal input/output cables;

• Power supply unit;

• External control unit;

• 220/110V power supply adapter and Altera ByteBlaster Cablewith necessary drivers (optional).

Actually, Denoiser Development Kit may be delivered inmono ordual modification. Dual supposes, that STC-H209 is provided withstereo noise-cancellation algorithm instead of common broadband fil-tering algorithm included inmono. In addition, linear and microphone

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20 CHAPTER 3. DENOISER DEVELOPMENT KIT

cables provided inmono kit are substituted with a single cable for ahigh-quality audio input from two external microphones fordual. Fi-nally, Denoiser Development Kit dual includes the special cable forstereo noise-cancellation demo.

Assembling Denoiser Development Kit

System requirements

For the broadband filtering adjustment software to operate properly, thePC should meet following requirements:

• Intel Celeron 266 MHz or better CPU;

• At least 64 Mb RAM;

• One free parallel port (LPT);

• MS Windows 98/2000/XP;

• Any windows-compatible sound card1.

Preparing Denoiser Development Kit for operation

Before you start operating DDK or adjusting Denoiser DSP there arecertain preparations to be made.

1. Installing STC-S209 software

The software is very simple and easy-to-use, so it does not in fact requireany installation. Just copyDenoiser.exeto your hard drive.

1It is necessary only if you are going to listen to effects made by your adjustmentsfor additional control.

ASSEMBLING DENOISER DEVELOPMENT KIT 21

2. Installing Altera ByteBlaster cable drivers

Installation of Altera ByteBlaster drivers is necessary for MS Windows2000/XP users. Note, that you should have administrator rights to do it.

To install the drivers launch Add/Remove Hardware wizard in theControl Panel. You will have to select hardware from the list manually.You should choose “Sound, video and game controllers” entry in theHardware Type list and then specify a driver file on your ByteBlasterinstallation CD. For more detailed instructions, please, refer to AlteraByteBlaster technical documentation.

Important!Note, that Altera ByteBlaster is optional DDK component. If youwere not provided with it, you may always purchase the cablefrom its vendor.

3. Connecting STC-H209 card to PC

To connect STC-H209 I/O card to the PC, please, follow these step-by-step instructions:

1. Ensure that Denoiser DSP Board is disconnected from its powersupply and the PC is switched off.

2. Connect STC-H230 card to STC-H210 upgrade card connector.

3. Connect your PC’s LPT port to the respective connector on STC-H230 card with Altera ByteBlaster download cable (seeFigure 3.1,4).

4. Connect flash access pins (seeFigure 2.2) with a jumper. This willenable you to save your adjustments to flash memory of DenoiserDSP.


Figure 3.1: STC-H209 (1), STC-H210 (2) and STC-H230 (3) cards withAltera ByteBlaster (4) connected to the latter

5. Connect the external control unit to the external control unit pinsshown onFigure 2.2. You may now use it to turn the noise-cancellation on and off. Ensure, that the switch is ‘on’.

6. Connect the power supply to the respective connector on STC-H210.

7. Connect the headphones or other playback equipment to the soundI/O card of your PC (if necessary).

8. Turn on the PC.

9. Press ‘clear flash’ button (Figure 3.1, 5) once.

Now you may save your adjustments to flash memory of DenoiserDSP (see alsoSound processingin the next section). Do not forget tofollow the same procedure every time you connect your DDK to the PC.

TUNING Denoiser DSP BROADBAND FILTERING 23

Tuning Denoiser DSP broadband filtering

After all the necessary drivers are installed and Denoiser DSP Board isproperly connected to the PC, you may start adjusting the board. Todo it runDenoiser.exefrom the hard drive of your PC. You should seeprogram main window (Figure 3.2) appear.

Figure 3.2: Denoiser DSP adjustment software main window

This window has four logical groups:

Noise reduction settingscontains built-in broadband noise-cancellationalgorithm adjustment parameters.

Hardware settings are adjustable parameters of signal input.

Sound processingpanel contains audio processing controls and visualrepresentation.


Default, Save, Save to Flashbuttons are necessary to save the adjust-ments.

Noise reduction settings

Reduce byslider adjusts the most important noise-cancellation param-eter – level of noise suppression. Available values range from 1 to 10.You should keep in mind, that high noise-reduction level may distortuseful signal along with removing the noise.

Just under this slider there is the bandpass filter panel. This filterwill eliminate high- and low-frequency noises. You mayEnable it witha flag in the checkbox and then set lower and upper bandpass border inHigh PassandLow Passfields.

Several additional noise-cancellation controls are brought togetherin the lower-left corner.Harmonics suppressioncheckbox turns onharmonic filter. Spectral andTime smoothing control smoothing offilter coefficients in spectral and time domain, respectively. They areused to minimize musical noises, which tend to appear at high levelsof noise reduction. Finally,Smooth lengthslider defines time of filteradjustment to spectrum variations. 3 seconds is recommended in com-mon cases, while for non-stationary noises it should be lowered to 1-2seconds. Extremely lowsmooth lengthwill, as a rule, greatly impairspeech quality.

Hardware settings

In this group you may select signalSampling rateand FFTFrame size.Available values for these parameters depend on Denoiser DSP Boardmodification. There are, however, basic guidelines for these settings: thegreatersampling rate you set, the largerframe sizeshould be. Note,however, that for quickly varying interferencesframe size should beminimized.


Sound processing

Sound processingpanel is necessary for controlling the effect of pro-cessing adjustments. To evaluate these effects you will have to specifya source audio file either manually inSource filestring, or by selectingit from the list. To browse for existing audio files pressLoad button inSound filesgroup.

The source file should contain a typical signal, similar to those,which will be later processed by Denoiser DSP Board. It should alsobe recorded as mono, 16-bit PCM and with a sampling rate supportedby your modification of Denoiser DSP Board (i.e. this sampling rateshould be available inHardware settings). After the file is successfullyloaded, this information will be automatically displayed inSource infofield. The program will also automatically create a target file, where itwill record the processed audio. Its name will be displayed inTargetfile string, where you may change it (by default the program will justadd CLR to source file name).

Process infopanel controls the processing and playback.You may start processing the source file with currentNoise reduc-

tion and Hardware settings by pressingStart ( ) button.Stopbutton( ) will stop the processing.Elapsed timeandTime left fields andthe progress bar just below them are useful for monitoring processingprogress.

You may also always play back source (unprocessed) and target(processed) files withPlay ( ) buttons. To stop playback pressStop( ). There are alsoVolume slider for playback signal level adjust-ment andPlayback progressindicator bar.

Finally, there is signal waveform window, where unprocessed signalwaveform is displayed in green and processed waveform – in blue. Toselect a phonogram fragment to play back or process, just move yourmouse pointer over it holding left mouse button. Right-clicking over awaveform window will remove the selection.


Buttons in the upper right corner of the main window are necessaryto save the processing parameters.

Savebutton will record your parameter values in a text file, whichmay be later viewed with any common text editor. To store the param-eters in the Denoiser DSP flash memory and use them for processing,pressSave to flash. If the program encounters any problems while sav-ing the parameters, it will display an appropriate message, create theerror log file (jam.log) and record all error information in it.

Important!Remember, that you have to follow the steps described in3 eachtime you connect your DDK to the PC.

If, for any reason, you wish to restore initial processing parametersjust pressDefault. Note, that it will restore only software parameters,save them to flash if you wish to bring Denoiser DSP to its initial state.

Signal input and output cables

Linear signal output (headphones) and input cables supplied with De-noiser DSP are shown onFigure 3.3. Input cable is supplied with a di-vider in order to be connected to microphone input of STC-H209 board.

Figures3.4and3.5show ONEMIC, TWO MIC and noise-cancellationdemo cable. The former one is supplied with Denoiser DevelopmentMono, while the latter two - with Denoiser Development Dual kit.


Figure 3.3: Signal output and input cables

Figure 3.4: ONEMIC and TWOMIC input cables


Figure 3.5: Stereo noise-cancellation cable

Note, that the input connector may be configured for microphone orlinear input. To do it, you should place theDivider on/off jumpers inan appropriate position. This jumper group is located between the inputand output connectors (seeFigure 2.2). CheckFigure 3.6for possiblejumper configurations.

Stereo noise-cancellation

Denoiser Development Kit Dual provides you with a possibility to per-form stereo noise-cancellation using the algorithm embedded in De-noiser DSP. There are three modes of stereo noise-cancellation:

1. You should connect a microphone, which receives a noisy signalto the right input channel and connect line output of the noisesource to theleft input channel. This mode is most efficient.

STEREO NOISE-CANCELLATION 29

Figure 3.6: Possible input configurations

2. If it is impossible to connect the noise source to Denoiser DSPline input, you may substitute it with a microphone placed nearthe noise source.

3. The third way to employ stereo noise-cancellation is to place bothleft and right channel microphones close to noise signal source.

Chapter 4

Delivery Set

Name Serial Number Notes

STC-H209 Denoiser DSP boardSTC-H210 Expansion boardSTC-H230 Upgrade boardSTC-S209 softwareONE MIC cableTWO MIC cableSignal input cableSignal output cableStereo cableExternal control unitPower supplyPower supply adapterAltera ByteBlaster cableMounting set (srews, spacers, nuts,spring washers – 4; washers – 8)Technical Description and Operat-ing Instructions

31

Appendix A

Set of cables for DDK mono

Figure A.1: Cables included in Denoiser Development Kit mono deliv-ery

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Documents

Denoiser DSP Board · 2013-11-24 · Denoiser DSP Board STC-H209 Denoiser DSP board is designed as one-channel board for noise reduction. Denoiser DSP provides noise-cancellation