wimax mimo circuit and system design
TRANSCRIPT
![Page 1: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/1.jpg)
WiMax MIMO Circuit and System Design
Presenter: Eldon Staggs
Authors:Jim DeLap, John Borelli, Tony Donisi, Eldon StaggsAnsoft Corporation
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FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
BSRCRANDOM
IFFT
SP
CYCLIC_PREFIXSP Sx ( )fx
SP
I
Q
I
Q
RITOCR
I
CTORIR
I
IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
Mobile WiMax System• WiMax System Modeling
– Behavioral, Circuit and Physical
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Agenda
Introduction to Mobile WiMax
System Architecture
MIMO Antennas
Receiver Circuit
Integration
Conclusion
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WiMAX - Mid Range IEEE Communication Standard
< 1 m Body Area Networks
< 10 m Personal Area Networks
< 100 m Local Area Networks
< 10 Km Metro Area Networks
> 10 Km Wide Area Networks
Range Standard
Our focus today is Mobile WiMAX, a standard designed to enable high data rate applications such as the wireless Internet.Our focus today is Mobile WiMAX, a standard designed to enable high data rate applications such as the wireless Internet.
802.16
•Last mile broadband wireless access
• 40Mbps capacity up to 10km
•OFDM with QPSK/QAM16/QAM64
• Fixed, Portable (walking) and MobileMobile (in car) options
802.16e• 63Mbps peak capacity up to 3km at 2.3,2.5 or 3.5GHz
• No line-of-sight required
today
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WiMAX Architecture Based on 2 Core Features: MIMO & OFDM
1. MIMO (Multiple Inputs Multiple Output = Many Antennas)– Advantage: More antennas means more data or reliability. For example,
if 2 TX and RX antennas are present, then data rate should double. Data rates will scale linearly.
– Challenge: How to design system so that interactions between multiple TX and RX are minimized.
Solutions, thus far, have emphasized 4 diversity schemes:
#1: #2: #3: #4: Space Time Coding
⎥⎦
⎤⎢⎣
⎡−
= *1
*2
21
SSSS
C
…Our examples today will illustrate how MIMO and OFDM can be simulated.Our examples today will illustrate how MIMO and OFDM can be simulated.
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WiMAX Architecture Based on 2 Core Features: MIMO & OFDM
Our examples today will illustrate how MIMO and OFDM can be simulated.Our examples today will illustrate how MIMO and OFDM can be simulated.
2. OFDM (Orthogonal Frequency Division Multiplexing)
– Advantages:→ Relative immunity to multi-path effects→ Multiplexing schemes, using IFFT & FFT, are easily implemented→ Low sensitivity to time synchronization errors→ Tuned sub-channel receiver filters are not required (unlike
conventional FDM)
– Challenges:→ Sensitive to Doppler shift→ Sensitive to frequency synchronization→ High peak-to-average-power ratio (PAPR), requiring more
expensive transmitter circuitry, and possibly lowering power efficiency
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Mobile WiMax Details• Flexibility
– All aspects can change dynamically to suit the channel
• WiMax MIMO 2x2 Configuration– Beamforming– Spatial Multiplexing
• Complicated algorithms for data rate increase• Data rate scales with min(Ntx,Nrx) antennas
– Space Time Coding• Diversity gain with easy implementation
• OFDM Implementation– Sub-carrier and Symbol times fixed– BW usage dictated by IFFT length– Downlink Data Rate
…
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System Architecture
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
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FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
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FL=2.3GHzFU=2.7GHz
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BSRCRANDOM
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SPCYCLIC_PREFIX
SP Sx ( )fx
SP
I
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RITOCR
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I
IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
BehavioralBehavioral
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Baseband Modeling• OFDM Modeling
– Guard Band– Cyclic Prefix
• Delay Spread & Multipath Immunity
• QAM Modulation– 4/16/64 Supported BSRC
RANDOM
CMUX
CMUX
CCONSTIFFT
SP
CCONST
CMUX
CYCLIC_PREFIX
BSRCRANDOM
SP
Sx
( ) f
x
SP
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BSRCRANDOM
IFFT
CYCLIC_PREFIX
I
Q
I
Q
RITOC
R
I
CTORI
R
I
h11
h22
h21
h12
Tx Rx
U2Channel3
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti Encoder
IFFT
CYCLIC_PREFIX
SP
Null_Remover2
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
Pilot_Null_Insertion1Preamble
Preamble_Insertion2
h11h21h12h22
Preamble_Removal2
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
Baseband Modeling• Channel Detection
– Excite Transmit Antennas separately• Initial frequency estimation
– Pilots• Dynamic estimation
…
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BSRCRANDOM
I
Q
RITOC
R
I
SP
SP
SP
SP
h11
h22
h21
h12
Tx Rx
U2Channel
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti Encoderr1
r2
[~s2 ~s1]
Alamouti DecoderI
Q
CTORI
R
I
SP
SP
BERP
ber_stc
SP
SP
Baseband Modeling
• Space Time Coding– Orthogonal Alamouti Codes
• SISO vs MIMO– Diversity gain
⎥⎦
⎤⎢⎣
⎡−
= *1
*2
21
SSSS
C
)]1[]0[(~
)]1[]0[(~
*1
1
*22
*2
1
*11
jjj
Mr
j
j
jjj
Mr
j
j
rhrhS
rhrhS
⋅+⋅=
⋅+⋅=
∑
∑
=
=
…
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MIMO Antenna Design
FL=2.3GHzFU=2.7GHz
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SP
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IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
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Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
PhysicalPhysical
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WiMax Physical Channel• Simplified Channel Model
– Path Loss with Friis Transmission equation – Non-Ideal effects often ignored
• Element coupling, Mismatch, Orientation– Single value for Antenna gains
• More Accurate Channel Model– Full-wave 3D EM modeling with HFSS– System Non-linearities
• Multi-path, Fading, etc.
2
4Pr
⎟⎠⎞
⎜⎝⎛=
RGtGr
Pt πλ
Rrtrtrtrrtt eaa
RGG
Ptα
πλφθφθ −
⋅Γ−Γ−⎟⎠⎞
⎜⎝⎛=
2*222
)1)(1(4
),(),(Pr
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WiMax Physical Channel• Antenna Configurations
– SISO and full 2x2 MIMO– Designs centered at 2.5GHz
• Mobile Station– Laptop with WiMax Modem PC Card – Simple Radiating Mononpoles
• Base Station– Reflector backed Dipoles
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Mobile Station Antenna• Tuned Monopole • Monopole Response
– Far Field– Return Loss
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Base Station Antenna• Reflector Backed Dipole
– Optimized for Directivity• Dipole Response
– Far Field– Return Loss
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Link Simulation
• Physical Channel– Antennas modeled– How to simulate link between?
• Utilize Ansoft HFSS Datalink– Fields from one drive another– Large separation without modeling air
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HFSS Datalink
• Source Fields of Radiation Boundary– Imposed on target model with loss and phase
Source ModelSource Model Target ModelTarget Model
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MIMO Datalink
Laptop Model with Dual Monopoles
BS Model with Dual Dipoles and reflector
Fields from Source model radiation BCMapped to target model using a Far FieldIncident Wave
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MIMO Physical ChannelDatalink
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MIMO Physical ChannelCircuit Model
• HFSS-HFSS Datalink maps fields from a source volume to the target volume
• Q: How does this translate to a working circuit model ?
• A: Utilize the [Z] matrix in Nexxim1. Excite each antenna in system with a 1 A current source2. Using Datalink, measure O.C. voltage at all the other antennas3. Construct [Z] matrix from Voltages
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MIMO Physical ChannelCircuit Model
• Voltage values extracted as real/imaginary pairs
• Assembled into [Z] matrixjkIj
iij
kIVZ
≠=
=,0
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WiMax Circuit Design
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
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FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
BSRCRANDOM
IFFT
SPCYCLIC_PREFIX
SP Sx ( )fx
SP
I
Q
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Q
RITOCR
I
CTORIR
I
IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
CircuitCircuit
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Antenna/Circuit Test Bench
• 2x2 MIMO Channel• Dual Receiver
– 2.5GHz to Baseband
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WiMax Single RX Block Diagram
• Receiver per Antenna– Variable Gain LNA– Active Balun– IQ Mixer– Baseband Filter– AGC
• UMC 0.13um CMOS
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WiMax Receiver• Variable-Gain LNA
– 2-stage, inductively-loaded cascode topology– output follower stage gain control.
12mA 12mA
2mA
RFin
RFou
GC
AVD
D
AGN
D
AGND1
PD
Ibias
AGND1
IbiasPDAVDD
AGND1
U31Nexxim8
l=25uw=25u
mimcaps_rf
M=1
c_tot_m=0.669p
l_cr
20k_
rfdo=1
50u
w=5
.7u
s=2.
52u
nt=7
.5
p_ls
=3.8
2n
l=35uw=35u
mimcaps_rf
M=1
c_tot_m=1.286p
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l_cr20k_rf
do=150uw=2.5us=2.5u
nt=7.5
p_ls=7.42n
n_bpw_12_rf
nf=16
lf=0.12uwf=3u
M=4wt=48u
n_bpw_12_rf
nf=16
lf=0.12uwf=3u
M=4wt=48u
l_cr20k_rf
do=75uw
=6.3us=1.79unt=3
p_ls=0.43nl_cr20k_rf
do=149uw
=5.2us=1.8unt=5
p_ls=3.42n
l=26.6uw=26.6u
mimcaps_rf
M=1
c_tot_m=0.754p
l=100uw=100u
mimcaps_rf
M=1
c_tot_m=10.174p
n_bpw_12_rf
nf=16
lf=0.12uwf=3u
M=4wt=48u
n_bpw_12_rf
nf=16
lf=0.12uwf=3u
M=4wt=48u
l_cr20k_rf
do=75uw
=5.6us=2.5unt=2.5 p_ls=0.38n
l_cr20k_rf
do=150uw=2.7us=2.5u
nt=7.5
p_ls=7.13n
l_cr20k_rf
do=149uw
=5.2us=1.8unt=7
p_ls=4.57n
l=20uw
=2um
=1rnhr_rfr_zbt_m
=9.96k
l=26.6uw=26.6u
mimcaps_rf
M=1
c_tot_m=0.754p
n_bpw_12_rf
nf=16
lf=0.12uwf=1.8u
M=1wt=28.8u
n_bpw_12_rf
nf=16
lf=0.12uwf=1.8u
M=1wt=28.8u
n_bpw_12_rf
nf=16
lf=0.12uwf=1.8u
M=1wt=28.8u
l=20uw
=2um
=1rnhr_rfr_zbt_m
=9.96k
l=99.77uw=99.77u
mimcaps_rf
M=1
c_tot_m=10.128p
varmis_12_rf
w=10unf=8l=2u
m=1
cox_m=1710.5f
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AVDDM
IFp
IFn
RFp
RFn
PD
Ibias
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=1wt=80u
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=1wt=80u
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=1wt=80u
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=1wt=80u
l=20uw
=2um
=8.5 rnhr_rfr_zbt_m
=1.172k
l=20uw
=2um
=8.5 rnhr_rfr_zbt_m
=1.172k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=4wt=80u
n_bpw_12_rf
nf=16
lf=0.12uwf=5u
M=4wt=80u
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=20uw
=2um
=1
rnhr_rfr_zbt_m
=9.96k
l=35
.7u
w=5
0u
mim
caps
_rf
M=1
c_to
t_m
=1.8
51p
varmis_12_rf
w=10u
nf=8l=2u
m=1 cox_m
=1710.5f
varmis_12_rf
w=10u
nf=8l=2u
m=1 cox_m
=1710.5f
l=100uw=100u
mimcaps_rf
M=1
c_tot_m=10.174pl=100u
w=100u
mimcaps_rf
M=1
c_tot_m=10.174p
IbiasPDAVDD
AGND1
U98Nexxim15
WiMax Receiver• I-Q Mixer
– Dual, resistively-loaded Gilbert Cell cores– Folded RF feeds
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0
LPF_Vtun
AVDD
BBIp
BBIn
IOutp
IOutn
VDDVtunOutp
Outn
Inp
InnGND
U155LPF10
VDD
Vctrl
p
Vctrl
n
Vin
Vinn Voutn
Vout
GN
Ddu
mp
GND
I350u
U156
Stg20
V1560 V1563 V1564 V1565 V1566 V1567
VDD
GND
Iinp
VoutnIinn
Voutp
I300uI500u_tia
PD
U163
OpStg14Inp
Inn
VDD
GND
Outp
Outn
I250u
PD
U154HPF18
VDD
Vctrl
pVc
trln
Vin
Vinn Ioutn
GN
Ddu
mp
GND
Ioutp
CM
ref
I350uI50u_cm
U161
Stg21
Bias
Inp
Inn
VDD
Outn
Outp
U158
HPF19
I50u_cm1I350u_stg2i
WiMax Receiver• Baseband Filter & AGC
– Buffered active (gm-C)/passive bandpass– Integrated Automatic Gain Control.
VDD
Vct
rlpVc
trln
Vin Vinn
Ioutn
GNDdump GNDdump
GND
Ioutp
CMref
I350u
I50u_cm
n_12_rf
nf=16
lf=0.2uwf=7.2u
M=2wt=115.2u
n_12_rf
nf=16
lf=0.2uwf=7.2u
M=2wt=115.2u
p_12_rf
nf=12
lf=0.15uwf=9.6u
M=1wt=115.2u
p_12_rf
nf=12
lf=0.15uwf=9.6u
M=1wt=115.2u
p_12_rf
nf=12
lf=0.15uwf=9.6u
M=7wt=115.2u
p_12_rf
nf=12
lf=0.15uwf=9.6u
M=7wt=115.2u
p_12_rf
nf=12
lf=0.3uwf=9.6u
M=14wt=115.2u
p_12_rf
nf=12
lf=0.3uwf=9.6u
M=14wt=115.2u
p_12_rf
nf=12
lf=0.2uwf=9.6u
M=10wt=115.2u
p_12_rf
nf=12
lf=0.2uwf=9.6u
M=10wt=115.2u
n_12_rf
nf=10
lf=0.2uwf=7.2u
M=2wt=72u
n_12_rf
nf=10
lf=0.2uwf=7.2u
M=2wt=72u
n_12_rf
nf=10
lf=0.2uwf=7.2u
M=1wt=72u
n_12_rf
nf=8
lf=0.2uwf=7.2u
M=2wt=57.6u
n_12_rf
nf=16
lf=0.3uwf=7.2u
M=4wt=115.2u
n_12_rf
nf=16
lf=0.3uwf=7.2u
M=4wt=115.2u
l=5.3uw=2um=20
rnhr_rfr_zbt_m=0.124k
Vsense
Vref
GND
Vout
VDD
I50u_s
U386
CMamp11
l=10uw=1um=1 rnhr_rf
r_zbt_m=10.089k
l=10uw=1um=1
rnhr_rfr_zbt_m=10.089k
l=10uw=1um=1
rnhr_rfr_zbt_m=10.089k
l=10uw=1um=1
rnhr_rfr_zbt_m=10.089k
Bias
BiasVfb Vfb
net_cmnet_cm
![Page 29: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/29.jpg)
WiMax RX Linearity Metrics
• Compression– Single RF & LO to baseband
• Third Order Intercept– Two RF & Single LO– Swept & Spectral Response
![Page 30: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/30.jpg)
Integration
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
BSRCRANDOM
IFFT
SPCYCLIC_PREFIX
SP Sx ( )fx
SP
I
Q
I
Q
RITOCR
I
CTORIR
I
IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
CircuitCircuit
PhysicalPhysicalBehavioralBehavioral
![Page 31: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/31.jpg)
Complete WiMax System• Baseband Tx/Rx
– QAM, STC Encoder/Decoder, OFDM
• RF Tx/Rx– Quadrature Mixing, Amplification, Filtering
• Channel– SISO & MIMO, Link, Noise
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
FL=2.3GHzFU=2.7GHz
0.5
BSRCRANDOM
IFFT
SP
CYCLIC_PREFIX
SP Sx ( )fx
SP
I
Q
I
Q
RITOCR
I
CTORIR
I
IFFT
CYCLIC_PREFIX
SP
Null_Remover1
CYCLIC_REMOVE
CYCLIC_REMOVE
FFT
FFT
SP SP
SP
SP SPSP
Pilot_Null_Insertion2
[s2 s1]
[-s2* s1]
[s1* s2]
Alamouti EncoderPreamble
Preamble_Insertion1
T/R SwitchPowerAmp
T/R Switch
LNA
Baseband Transmitter
Baseband Receiver
RF Transmitter
RF Receiver
Channel
h11h21h12h22
Preamble_Removal1
r1
r2
[~s2 ~s1]
Alamouti Decoder
h11h21h12h22
SP
OFDM_Tx
OFDM_Rx
SP
SP
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHz
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
45-45
Fcarrier=2.5GHz
Fcutoff=10MHzAGC_Gain=100
Sx ( )fx
BehavioralBehavioral
Circuit + BehavioralCircuit + Behavioral
PhysicalPhysical
![Page 32: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/32.jpg)
Complete WiMax System• Behavioral and Physical
– SISO vs MIMO (Diversity gain)– EVM Distortion
• Circuit and Physical– Nonlinear interactions– Loading effects
• Behavioral, Physical and Circuit– BER distortion– Multipath degradation
![Page 33: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/33.jpg)
Conclusion• WiMax System Modeling
– HFSS dynamic link for Channel– Nexxim for NL circuit impact– Unique Integration of Physical, Circuit & Behavioral
• HFSS, Nexxim & Designer together help you pave the way for:
First Pass System SuccessFirst Pass System Success
![Page 34: WiMax MIMO Circuit and System Design](https://reader034.vdocuments.site/reader034/viewer/2022042504/5477da5eb4af9f76108b49e3/html5/thumbnails/34.jpg)
References• [1] IEEE Std 802.16-14 Air Interface for Fixed Broadband Wireless Access
Systems• [2] IEEE Std 802.16e-2005 Air Interface for Fixed Broadband Wireless
Access Systems• [3] Mobile WiMax – Part I: A Technical Overview and Performance
Evaluation– WiMax Forum
• [4]MIMO System Technology for Wireless Communications– By George Tsoulos
• [5] Digital Communications by Bernard Sklar• [6] OFDM for Wireless Multimedia Communications
– by Richard van Nee and Ramjee Prasad, Artech House Publishers• [7] The suitability of OFDM as a modulation technique for wireless
telecommunications, with a CDMA comparison– by Eric Lawrey, October 1997
• [8] Modeling an Advance Communication System based on OFDM– By Eldon Staggs, September 2000