transceiver architectures for impulse radio systems with m...

Transceiver Architectures for Impulse Radio Systems with M-ary Modulation Schemes

EDUARDO CANO

University of Limerick

7th November 2005

Wireless Access Research

OUTLINE

• DIRECT SEQUENCE IMPULSE RADIO TRANSMISSION FORMAT

• TRANSMITTER PARAMETERS DESIGN:

- M-ARY MODULATION SCHEMES

- PULSE SHAPE CONSTRUCTION

• RECEIVER STRUCTURE FOR M-ARY MODULATED IR SYSTEMS

• AIMS AND FUTURE WORK

• UWB IN THE NCNRC PROJECT


DIRECT SEQUENCE IMPULSE RADIO (DS-IR)• Concept:

- Transmission of sub-nanosecond pulses.

- The symbol time is divided into frames. Each frame is composed of slots.

- Each user transmits pulses per symbol (1 pulse per frame).

- TH Code sequence assigns the corresponding slot and DS sequence gives the polarity

sN

sNhN

4=sN3=UN 4=hN

USER 2 ,...]2,0,3,0[)2( =THC

USER 3 ,...]3,2,1,3[)3( =THC

USER 1,...]0,1,0,2[)1( =THC

,...]1,1,1,1[)1( −−=DSC

ccsfsss TNNTNTR 111 ===

sT

cTfT

• Equation of the Transmitted Signal:

( ) ( )( );)()()( )()()()()( �+∞

−∞=

−−−=j

uc

uTHfi

uDS

uuTx kdTjCjTtwjCkAts δβ � �sNjk =

DS-IR TRANSCEIVER BLOCK DIAGRAM

BIT SOURCE

OSCILLATOR

TH CODE GENERATOR

DS CODE GENERATORDETECTION

UNITDEMODULATOR

MODULATOR

PULSE GENERATOR

PROGRAMMABLE TIME DELAY


TRANSMITTER DESIGN: MODULATOR (V)

Modulation ParametersBit RateModulation

whsb TNN

MR

)(log 2=

( )[ ]whsb TMNN

MR

+−=

δ1)(log2

��

��

� +�

��

−=

whs

b

TM

NN

MR

δ12

)(log2

( )[ ]whsb TMNN

MR

+−=

δ1)(log

2

2

212 MMM =

1-)1logb(2)( 2)( += Mkkuβ

{ }1)(log10 12),..,(),()( −∈ Mi wtwtwtw

[ ]{ })1)log)(log1((b),...,2log(b 22122 −++++= kMMkMkGi

[ ]{ })log)1((b),...,2loglog(b)( 2122)( MkMMkGkd u +++=

1-)1logb(2)( 2)( += Mkkuβ

[ ]{ })log)1((b),...,2log(b)( 22)( MkMkGkd u ++=

)()( twtw Txi = i∀

)()( twtw Txi = i∀

( ) 1)( =kuβ k∀

[ ]{ })log)1((b),...,1log(b)( 22)( MkMkGkd u ++=

)()( twtw Txi = i∀( ) 0)( =kd u k∀

[ ]{ } MMkMkGku −+++= 1)log)1((b),...,1log(b2)( 22)(β

� �sNjk = ( ) ��

��

−∈ 1log

,..,2,1,02 MN

k b

M-PPM

M-BPSPM

M-BM

M-PAM

( ) ( )( );)()()( )()()()()( �+∞

−∞=

−−−=j

uc

uTHfi

uDS

uuTx kdTjCjTtwjCkAts δβ

BIT SOURCE

TH CODE GENERATOR

DS CODE GENERATOR

PROGRAM. TIME DELAY

PULSE GENERATOR

)(twTx

CLOCK OSCILLATOR

MODULATOR UNIT

M-ary PAM

M-ary PPM

M-ary BM

M-ary BPSPM

)()( ts uTx

�(u)DSc

b

� −j

cu

THD Tjct ))(( )(δ

� −j

fD jTt )(δ� −−−

j

uc

uTHfD

uuDS kdTjcjTtkjc ))()(()()( )()()()( δδβ

� −j

D kdt ))(( δδ

DS-IR TRANSMITTER STRUCTURE

BIT SOURCE

TH CODE GENERATOR

DS CODE GENERATOR

PROGRAM. TIME DELAY

PULSE GENERATOR

)(twTx

CLOCK OSCILLATOR

M-ary PAM MODULATOR

)()( ts uTx

�(u)DSc

b

� −j

fD jTt )(δ

PROGR. UNIT( )δ,,, sb NNM

( )kbG { } -M-k 1G2 b

kb

DS-IR TRANSMITTER USING M-ary PAM

d

� −j

cu

THD Tjct ))(( )(δ

kb

� −−−j

uc

uTHfD


� −j

D kdt ))(( δδ

BIT SOURCE

TH CODE GENERATOR

DS CODE GENERATOR

PROGRAM. TIME DELAY

PULSE GENERATOR

)(twTx

CLOCK OSCILLATOR

M-ary PPM MODULATOR

)()( ts uTx

�(u)DSc

b

� −j

fD jTt )(δ


( )kbG 12 -c

kb

δ

[ ]111 ,..,=c

d

� −j

cu

THD Tjct ))(( )(δ

� −−−j

uc

uTHfD


DS-IR TRANSMITTER USING M-ary PPM

� −j

D kdt ))(( δδ

BIT SOURCE

TH CODE GENERATOR

DS CODE GENERATOR

PROGRAM. TIME DELAY

PULSE GENERATOR

)(twTx

CLOCK OSCILLATOR

M-ary BM MODULATOR

)()( ts uTx

�(u)DSc

b

� −j

fD jTt )(δ


( )2G k,b 12 1, −kb

2k,b

δd

� −j

cu

THD Tjct ))(( )(δ

1k,b

� −−−j

uc

uTHfD


DS-IR TRANSMITTER USING M-ary BM

� −j

D kdt ))(( δδ

BIT SOURCE

TH CODE GENERATOR

DS CODE GENERATOR

PROGRAM. TIME DELAY

PULSE GENERATOR

)()( )(G 3,twtw

ki b=

CLOCK OSCILLATOR

M-ary BPSPM MODULATOR

)()( ts uTx

�(u)DSc

b

� −j

fD jTt )(δ

PROGR. UNIT( )δ,,, iNM b

δd

� −j

cu

THD Tjct ))(( )(δ

2k,b 1k,b

12 1, −kb( )2G k,b

( )3G k,b3k,b

� −−−j

uc

uTHfD


DS-IR TRANSMITTER USING M-ary BPSPM

� −j

D kdt ))(( δδ

PULSE SHAPE DESIGN

- Objectives for single pulse shape construction (M-PAM, M-PPM, M-BM)

1. Flexibility in the frequency domain. FCC and ETSI constraints.

2. Short and finite time duration Large Bandwidth

3. Easiness to implement and Low complexity4. Robust against jitter errors5. Narrowband Interference suppression

- Typical waveforms: High order derivatives of the Gaussian pulses, Modified HermitePolynomial pulses, Prolate Spheroidal Wave Functions (PSWF) pulse, composite of Gaussian monocycles and pulse constructions based on filter outputs.

- Objectives for M-PSM systems:1. The same 5 properties 2. Set of pulses that are orthogonal considering the antenna effects. 3. Pulses with same length, energy and similar bandwidth

RECEIVED SIGNAL

)()()(),()(),()(1 2 1

)()()()1()1()1()1( tntntsttsttr NBI

L

i

Nu

u

L

i

ui

uRx

uiiRxi

P P

++−+−=� ��= = =

τταττα

Desired signal Multiple Access Interference NBI AWGN

- Narrowband Interference

��

��

��

��

��

��

�−ℜ= � �

= −=

− tfjN

i

N

Nks

iTtT

jk

jkNBIc

bs

eiTtpedtI ππ

2

1

2/

2/

)(2

, )()(

- Multipath fading channel

�=

−=PL

i

uiD

ui

u ttth1

)()()( )(),(),( τδτατ

-

14.18ns

10.38ns

5.05ns

M.E.D

61.5414.28ns4-10mnoCM3

-25ns>10mnoCM4

36.18.03ns0-4mnoCM2

245.28ns0-4myesCM1

NP (85%)RANGELOS/NLOSCM 2RMSσ

...

CASE M-BM: BANK OF CORRELATORS RECEIVER- The Bank of Correlators receiver is optimum when AWGN is the only distortion phenomenon

- The M-BM Receiver is formed by M/2 correlator units

� −−−=j

cTHfRxDSi iTjCjTtwjCz ))(()( )1()1()1( δ

{ }��

��

== ��−

=

+−

−

1

0

)1( )1( )()(maxmaxˆs

fb

fb

N

j

TjiT

jTiT iii tztrys

{ }issignˆ =BPSKs

{ }isGDˆ =PPMs

1z

12

−Mz

0z

( )� �−

=

⋅1

0

Ns

j T f

dt

( )� �−

=

⋅1

0

Ns

j T f

dt

( )� �−

=

⋅1

0

Ns

j T f

dt

max{|y

i|}

)(tr

is

0y

1y

12

−My

BPSKs

PPMsGRAY DEMAPPING

P/Ss.

CASE M-BM: CONVENTIONAL RAKE RECEIVER- RAKE receiver gathers the multipath energy

{ }��

��

��

��

��

��

−== � ��−

=

−

=

−+−

−−

1

1

1

0

)1( )1( )()(*maxmaxˆR s

mfb

mfb

L

m

N

j

TjiT

jTiT mimii tztrcysτ

ττ

- RAKE unit combining weights:

- MRC:

- MMSE:

{ }issignˆ =BPSKs

{ }isGDˆ =PPMs

[ ]110 ,...,, −== Lc αααβT

nRc β1−=( ) { }

��

��

�

+≈ H

v

NBIcivn zzRe

R

BWFVNIR

NR

)0(22)0(

2

2

0

22

−Mz

)(tr

is

0y

BPSKs

GRAY DEMAPPING

P/Ss

0z

22

−My

12

−My

PPMs

0τ

1−RLτ

( )� �−

=

⋅1

0

Ns

j T f

dt

( )� �−

=

⋅1

0

Ns

j T f

dt

1,0x

1,0 −RLx

*0c

*1−RLc

ΣSRAKE 0

SRAKE

SRAKE 22

−M

12

−M

...

...

12

−Mz

max{|y

i|}

.

CASE M-BM: REDUCED COMPLEXITY RAKE Rx (RC-RAKE)

- Total Number of Correlators: RC-RAKE: ; Conventional-RAKE:

- Template Waveform Definition:

• BPSK bit detection

• PPM bits detection:

�−

=

−=12

00 )(

M

jRx jtw δφ

))12(())1(2( δδφ −−−−−= itwitw RxRxi ;4

,..,2,1M

i =

� −−=j

cTHfiDSi TjCjTtjCz ))(()( )1()1()1( φ

RLM

NC �

��

+= 14 RL

MNC

2=

1z

)(tr

is

0y BPSKs

GRAY DEMAP

P/Ss

1y

4My

PPMs

SRAKE

SRAKE 1

12

−M

...

4Mz

0z

SRAKE 0

DE

CISIO

N

jis ,ˆ

)(2mod i

.

max{|y

i|}

.

SUMMARISE AND OBJECIVES OF RECEIVER DESIGN

M-BPSPM

M-BM

M-PPM

RC-RAKEConventional- RAKEModulation

2RMLNC = 4RMLNC =

2RMLNC = RLMNC )14( +=

RMLNC = 2RMLNC =

- Recap:

- Objectives:

- To reduce the receiver complexity for M-ary modulated IR systems keeping very

similar BER performance.

- To apply channel estimation mechanism Template pulses estimation.

- To use the minimum number of fingers within a RAKE structure (SRAKE, PRAKE)

and apply optimum finger assignment algorithms.

AIMS and FUTURE WORK

Working on:• The analytical BER and channel capacity expressions of M-BM, M-BPSPM, M-PPM and M-PAM using DS-IR as a Transmission format.

• Power Spectral Density of the Transmitted signal for DS-IR and TH systems using M-PSM Systems

• The analysis of the reduced complexity receiver implementation through BER simulations.

• Channel estimation and finger assignment algorithms for RAKE receiver.

Objectives:1) For a fixed BER value and low number of correlators at the receiver, what modulation scheme provides me the maximum data rate in a system with low, medium and high load (MUI) and with/without multipath environment?

2) For a fixed data rate value and low number of correlators at the receiver, what modulation scheme provides me the best BER performance in a system with low, medium and high load (MUI) and with/without multipath environment?

3) To compare conventional RAKE and reduce complexity RAKE structures: How many correlators I need to achieve a fixed BER value and fixed high data rate value for each modulation scheme?

4) If using M-BPSPM which constellation offers better performance (M1? M2?)

NCNRC PROJECT

• SFI – NCNRC (National Communications Network Research Centre )- Four year project (2004-2008)- Universities: Dublin Institute Technology, NUI Maynooth, and University of Limerick.- Industrial partners: Intel Shannon, Corvil.

• The goals:- To develop, demonstrate and prove techniques for measurement-based resource allocation in next generation heterogeneous wireless networks - Act as a focal point for wireless research in Ireland.

• Work packages:WP1 Operation of the 802.11e MAC MechanismWP2 WLAN Traffic ProbeWP3 RRC AlgorithmWP4 Admission ControlWP5 Exploiting Traffic ElasticityWP6 Experimental 802.11e TestingWP7 Architectures and Prototypes for Wireless Nodes

- Implementation, evaluation and testbed Integration of an UWB TransceiverWP8 Radio Resource ManagementWP9 Distributed architectures for QoS and Low PowerWP10 Wireless test-bed development

Satellite FES

Broadcast Networks(DAB, DVB-T)

TheInternet

10.220.12.x

SPP VoIPSignalling Gateway

MIP CallControl

3G/UMTS

GSM / GPRS

IP-based micro-mobility WLANs

ULMAN& Milford

…

ISPSIP Proxy Server

PANS

LOGICAL TESTBED VIEW

VoIP / SIP / MIPSPP/ CoMo /

UWB/Tx/Rx

3G

Bench Lab/F1 Extended/Virtual

WLAN: ULMAN - Extended

Low Power:BlackFin

TB1

RRM / MM

Power Saving

UL TESTBED

ULMAN TESTBED SCENARIOS

Technologies802.11a802.11b802.11e802.11g802.11n802.16

Point to Point

Point to Multipoint{Full, Partial} Mesh

Point to Multipoint{Full, Partial} Mesh

Interference/Interoperabilityfrom other nodes, technologies

Routing ProtocolsAODVDSRTORADSDVZPRCBRPIMEP

2 Nodes

5 Nodes 5-10 Nodes

ApplicationsWebEmailVoiceVideo StreamingVideo Conference

MetricsEnd-to-end data throughputEnd-to-end data delayRoute Acquisition TimeOut-of-Order DeliveryEfficiency

Performance parametersNetwork sizeNetwork connectivityTopological rate of changeLink capacityFraction of unidirectional linksTraffic patternsMobility

��

��

• ULMAN is a flexible testbed platform.• It currently supports IEEE 802.11 technology• Other transmission technologies will be integrated in the testbed, such as UWB.

UWB INPUTS IN THE NCNRC PROJECT• Tasks:

- Phase 1 (+/- 2 years):

- Evaluation and simulation of UWB transceiver

- Hardware implementation. UWB processor boards.

- Multiband UWB vs IR based systems.

- Results: BER, channel capacity, co-existence with IEEE 802.11x systems, etc.

- Phase 2 (+/- 1.5 years)

- Testbed integration:

- Off the shelve (Singleband and Multiband UWB ) PCMCIA Card

- FPGA chip?

- Co-existence analysis with IEEE 802.11x and UMTS.

- MAC implementation and RRM strategies.

UWB HARDWARE IMPLEMENTATION BLOCK DIAGRAM

Native MatlabCode for UWB Tx

C ++ Code Conversion of Tx

Compile and Build code in TI Code Composer Studio

DSK 6416 UWB Transmitter

Information Source

Native MatlabCode for UWB Rx

C ++ Code Conversion of Rx

Compile and Build code in TI Code Composer Studio

DSK 6416 UWB Receiver

Information Sink

UWB TRANSMITTER AND RECEIVER PROCESSORS

9cm

11cmSupports two PCMCIA Card

16cmPCM9373

Power supply

ULMAN NODE

THANK YOU

transceiver architectures for impulse radio systems with m...

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