Sub-Nyquist System Optimization

By: Daniel Barsky Natalie PistunovichSupervisors: Rolf Hilgendorf Inna Rivkin

Final Presentation

Outline

Previous workTest environment descriptionTest resultsConclusionsFuture work

Previous Work

Reminder – Pre-simulation analysis

Memory

Controller

.

.

.

A†

CTF

Expander DSP

Support Change Detector

Q-FrameOMP

FPGA 1 FPGA 2 FPGA 3

73%

98% 75%

Reminder – Pre-simulation analysis (Cont.)

Timeline

New IncomingSample

Expander Delay

Q-Frame Delay

3.5usec

OMP Delay

11usec

Pseudo-Inverse Delay

5usec

Reconstruction Delay

Sample readyFor reconstruction

Reconstruction Delay: Expander - ~15 cycles (@120MHz) CTF – ~1450 cycles (@120 MHz) DSP - ~500 cycles (@120 MHz)

Test Environment

Test Environment Overview - Matlab

txt

Filter Coefficients

txt

A Matrix

txt

Beta

General Datatxt

Beta

txt

Filter Coefficients

txt

A Matrix

Test Environment Overview – Matlab (Cont.)

txt

Input Data

txt

N

txt

N_frame

txt

Threshold

txt

Support

txt

Input Data

txt

N

txt

N_frame

txt

Threshold

txt

Support

Dataset_1 Dataset_2 Dataset_3

Test Environment Overview – Matlab (Cont.)

VHDL

Matlab_pack

...\General Data…\Dataset_1…\Dataset_2…\Dataset_3

VHDL

Matlab_pack

Test Environment Overview – Modelsim (Cont.)

CTF

Expander

Su

pp

lyIn

pu

tS

am

ple

s

Input Samples

N

N_frame

Threshold DSPSCD

Samples FIFO

Filter Coefficient

FIFOFilter Coefficients

Expanded Samples

RecalculateSupport

Support

DelayedSamples

A Matri

xβ

A Matri

xRecord

Reconstructed

Data

Simulation Controller

Filter Coefficients FIFO ModuleReads the filter coefficients from

a fileUpon receiving a REQ, outputs a

line of 7 coefficients and an ACK signal

Test Environment Overview - Modelsim

CTF

Expander

Su

pp

lyIn

pu

tS

am

ple

s

Input Samples

N

N_frame

Threshold DSPSCD

Samples FIFO

Filter Coefficient

FIFOFilter Coefficients

Expanded Samples

RecalculateSupport

Support

DelayedSamples

A Matri

xβ

A Matri

xRecord

Reconstructed

Data

Simulation Controller

Supply Samples Module

Reads from the files generated by Matlab: The input samples The N, N_frame, Threshold values The correct support

Upon receiving a positive pulse on the OE signal, starts generating the input samples

Supply Samples Module (Cont.)

FSM:

IdleOpens the first Dataset files (input samples,Nframe , threshold) and waits for an OE command

Read next datas

et

Done

OEReads samples from the relevantdataset and feeds them to the expander

Dataset i<3doneWhen the dataset samples are done,

reads the samples and data for the nextdataset Dataset 3 doneWhen all samples are done, do nothing

Test Environment Overview – Modelsim (Cont.)

CTF

Expander

Su

pp

lyIn

pu

tS

am

ple

s

Input Samples

N

N_frame

Threshold DSPSCD

Samples FIFO

Filter Coefficient

FIFOFilter Coefficients

Expanded Samples

RecalculateSupport

Support

DelayedSamples

A Matri

xβ

A Matri

xRecord

Reconstructed

Data

Simulation Controller

A matrix, β coefficient modulesRead the appropriate data fromA fileUpon receiving an address,

outputThe appropriate data

Test Environment Overview – Modelsim (Cont.)

CTF

Expander

Su

pp

lyIn

pu

tS

am

ple

s

Input Samples

N

N_frame

Threshold DSPSCD

Samples FIFO

Filter Coefficient

FIFOFilter Coefficients

Expanded Samples

RecalculateSupport

Support

DelayedSamples

A Matri

xβ

A Matri

xRecord

Reconstructed

Data

Simulation Controller

Samples FIFO module

Upon receiving a WE, stores incoming samples from the expander

Upon receiving OE, outputs stored samples to the DSP for reconstruction

Maximum FIFO length – defined by a Generic

Actual FIFO length – 4294 samples (@20MHz)

Test Environment Overview – Modelsim (Cont.)

CTF

Expander

Su

pp

lyIn

pu

tS

am

ple

s

Input Samples

N

N_frame

Threshold DSPSCD

Samples FIFO

Filter Coefficient

FIFOFilter Coefficients

Expanded Samples

RecalculateSupport

Support

DelayedSamples

A Matri

xβ

A Matri

xRecord

Reconstructed

Data

Simulation Controller

Simulation Controller

The main part of the testbenchReceives all status signals from

all blocks, and sends control signalsto all blocks

Consists of 3 FSMs – Expander FSM, CTF FSM, DSP FSM

Simulation Controller (Cont.)

Expander FSM:

InitInitializes the expander and starts theprocess of loading the filter coefficients

Wait Read

y

Phase

Delay

Ready

InputSampl

es

Done

Counter

Samples Done

Waits until all coefficients have been loadedand the Expander is ready

Raises the “Data Valid” signal while supplyingzero samples (to generate phase shift)Raises the “Data Valid” signal and inputsreal samples to the ExpanderOnce the samples are finished, pauses theExpander

Simulation Controller (Cont.)

CTF FSM:

InitInitializes the CTF

Wait Read

yIdle

Ready

Wait DSP

Calculate

Support

SupportValid

DSP SupportACK

Support

Change

Waits until the CTF is readyInitiates the CTF support calculation andwaits for a “Support Valid” signalWaits until DSP acknowledges the newsupportWaits until the SCD indicates a changein the support, upon which time it willinitiate a recalculation of the support

Simulation Controller (Cont.)

DSP FSM:Wait

Support

DSP is ready and waiting for the CTF tocalculate a new support

Pseudo

Inverse

Support Change

Reconst-

ruction

DSP is calculating a new PseudoinversematrixPseudoinverse calculation done, samplesfrom the Samples FIFO are used for reconstruction

Support Valid

Pseudoinverse Done

SupportUnchanged

Simulation Results

Expander Initialization

Input Samples & Expander Operation

CTF Initialization

CTF Support Recovery (Incorrect)

CTF Support Recovery (Correct)

Sample FIFO

DSP Pseudoinverse Calculation

DSP Support Change Detector

DSP Support Change Detector (False Positives)

DSP Support Change Detector (False Positives)

DSP Support Change Detector (Failure to detect)

0 10 20 30 40 50 60 70 80 90-180

-160

-140

-120

-100

-80

-60

Frequency (MHz)

Pow

er/f

requ

ency

(dB

/Hz)

Spectrum of y1[n] (after expand)

0 10 20 30 40 50 60 70 80 90-180

-160

-140

-120

-100

-80

-60

-40

Frequency (MHz)

Pow

er/f

requ

ency

(dB

/Hz)

Reconstructed sequence #1

0 10 20 30 40 50 60 70 80 90-180

-160

-140

-120

-100

-80

-60

-40

Frequency (MHz)

Pow

er/f

requ

ency

(dB

/Hz)

Reconstructed sequence #2

Reconstruction Example #1 – AM + sine

0 10 20 30 40 50 60 70 80 90-170

-160

-150

-140

-130

-120

-110

-100

-90

-80

-70

Frequency (MHz)

Pow

er/f

requ

ency

(dB

/Hz)

Spectrum of y1[n] (after expand)

0 20 40 60 80-200

-190

-180

-170

-160

-150

-140

-130

-120

-110

-100

Frequency (MHz)

Pow

er/f

requ

ency

(dB

/Hz)

Reconstructed sequence #1

0 20 40 60 80-180

-160

-140

-120

-100

-80

-60

Frequency (MHz)P

ower

/fre

quen

cy (

dB/H

z)

Reconstructed sequence #2

Reconstruction Example #2 – AM + FM

Conclusions

Hardware Utilization

LEs Block RAM bits

DSP Half-Blocks

Previous Analysis (DSP Halfblocks)

Expander 43,856 5Mbit 448

CTF 31,000 6Mbit 604

DSP 62,913 1.2Mbit 752

Avaliable on Stratix III 260

203,520 15Mbit 768

21%

33% 58%

15%

40% 78%

31%

8% 98%

73%98%

75%

(based on synthesis results of the different groups, including arcitecture blocks)

Reconstruction Latency

Expander

CTF

DSP

15 Cycles

1087 Cycles

29,823 Cycles

Timeline

New IncomingSample

Expander Delay

CTF Delay

9.06usec

DSP Delay

248.5usec

Sample readyFor reconstruction

Timeline

New IncomingSample

Expander Delay CTF Delay

14.5usec

DSP Delay

5usec

Sample readyFor reconstruction

Previous Evaluation:

Further Conclusions

Support calculation is unstable, and extremely sensitive to input phase (relative to the NCO’s phase)

SCD is highly prone to misdetections & false positives!

The system seems to have more trouble with FM signals than with AM/sine

Future Work

Future Work

Characterize the dependency of the support calculation on the input phase

Use fewer resources at a higher clock frequency at the reconstruction stage - in an attempt to squeeze it in with the Expander

Reimplement Pseudoinverse to share resources with the CTF, to fit them both in the same FPGA

Simulate & integrate implementation

Gantt Chart

Finish Part A Project Report

Characterize CTF dependency on phase(Matlab+Modelsim)

Reimplement reconstruction block

Simulate reconstruction block

Extract MaMu from CTF

Reimplement Pseudoinverse block

Simulate pseudoinverse block

Synthesize blocks

Simulate system with new blocks

Synthesize & Integrate Blocks

Final Part B Presentation

Write Part B Project Book

3/10/2011 3/30/2011 4/19/2011 5/9/2011 5/29/2011 6/18/2011 7/8/2011 7/28/2011 8/17/2011 9/6/2011