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Marius Pesavento - marius.pesavento@mimoOn.de<br />
Willem Mulder - willem.mulder@mimoOn.de<br />
<strong>LTE</strong> Tutorial part 2<br />
<strong>Advanced</strong> <strong>topics</strong> <strong>in</strong> <strong>LTE</strong><br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
1
Outl<strong>in</strong>e<br />
<strong>Advanced</strong> <strong>topics</strong> <strong>in</strong> <strong>LTE</strong><br />
� The <strong>LTE</strong> MIMO modes<br />
� Codebook-based precod<strong>in</strong>g<br />
� Closed loop operation<br />
� CQI report<strong>in</strong>g modes<br />
� Us<strong>in</strong>g antenna port 5 (SDMA) techniques<br />
� Simulation results<br />
� Outlook <strong>LTE</strong> <strong>Advanced</strong><br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
2
MIMO Channel<br />
MIMO<br />
detector<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
3
MIMO Precod<strong>in</strong>g<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
optimum „Eigen“ precod<strong>in</strong>g<br />
requires perfect channel<br />
knowledge (CSI)<br />
at the Transmitter<br />
4
Parallel AWGN channels<br />
Equivalent SISO channels<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
5
Transmit/Receive beamform<strong>in</strong>g<br />
<strong>in</strong>terpretation<br />
Transmit<br />
Beamformer(s)<br />
Tx Beam 1<br />
Tx Beam 2<br />
Rx Beam 1<br />
Rx Beam 2<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Receive<br />
Beamformer(s)<br />
6
Codebook based<br />
Spatial Multiplex<strong>in</strong>g (SM)<br />
� Precod<strong>in</strong>g matrix is selected from codebook<br />
� Reduced signal<strong>in</strong>g at cost of quantization error (lose<br />
rate optimality)<br />
� Equivalent MIMO channels no longer parallel<br />
(decoupled), reduction <strong>in</strong> rate<br />
� Receiver matrix can be designed arbitrarily.<br />
In practice <strong>in</strong>terference among the streams not<br />
completely removed:<br />
� receive SINR for the k-th stream<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
7
TB 1<br />
TB 2<br />
MIMO Tx process<strong>in</strong>g blocks <strong>in</strong> <strong>LTE</strong><br />
(spatial MUX)<br />
� maximum 4 spatial streams (layers)<br />
� maximum 2 TBs (codewords), each with correspond<strong>in</strong>g MCS.<br />
� 2Tx: Code-book with 2 precod<strong>in</strong>g matrices (closed-loop)<br />
CR 1<br />
Turbo<br />
encoder<br />
Rate Match<br />
CR 2<br />
Turbo<br />
encoder<br />
Rate Match<br />
MS 1<br />
modulator<br />
MS 2<br />
modulator<br />
layer mapp<strong>in</strong>g<br />
2-MUX<br />
layer 0<br />
or<br />
1-MUX<br />
layer 1<br />
2-MUX<br />
or<br />
1-MUX<br />
layer 2<br />
layer 3<br />
Precod<strong>in</strong>g<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
� is selected from set of 16 precod<strong>in</strong>g matrices.<br />
� code conta<strong>in</strong>s matrices of type: (and column permutated versions)<br />
; ; ;<br />
Tx 0<br />
Tx 1<br />
Tx 2<br />
Tx 3<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
IFFT<br />
IFFT<br />
IFFT<br />
IFFT<br />
8
MIMO schemes<br />
� Transmit diversity<br />
� <strong>in</strong>crease the reliability of the l<strong>in</strong>k,<br />
migrate fad<strong>in</strong>g<br />
� diversity order / diversity ga<strong>in</strong>: number<br />
of <strong>in</strong>pendent replica (fades) of the signal<br />
� Spatial multiplex<strong>in</strong>g<br />
� <strong>in</strong>crease spectral efficiency<br />
� multiplex<strong>in</strong>g ga<strong>in</strong>: number of spatial<br />
streams transmitted on a timefrequency<br />
resource<br />
� upper-bounded by m<strong>in</strong>(M t,M r)<br />
� requires rich multipath environment ⇒<br />
full channel rank<br />
� Beamform<strong>in</strong>g (rank 1)<br />
� Tx and Rx beamform<strong>in</strong>g<br />
� array ga<strong>in</strong> through coherent comb<strong>in</strong><strong>in</strong>g<br />
<strong>in</strong>creases signal-to-noise-and<strong>in</strong>terference-ratio<br />
(SINR)<br />
� requires correlated antennas (e.g. <strong>in</strong><br />
L<strong>in</strong>e-Of-Sight transmission)<br />
multipath<br />
fad<strong>in</strong>g constructive or destuctive<br />
superposition<br />
LOS<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
⇒<br />
fad<strong>in</strong>g<br />
rank 1<br />
S<strong>in</strong>gle stream<br />
only!<br />
9
DL-MIMO modes <strong>in</strong> <strong>LTE</strong><br />
� S<strong>in</strong>gle antenna port (no MIMO)<br />
� Transmit Diversity (TD), space-frequency Alamouti<br />
code<br />
� Open-loop Spatial Multiplex<strong>in</strong>g (SM)<br />
� Closed-loop SM<br />
� Multi-User (MU) MIMO<br />
� Rank 1 closed-loop SM (compressed control<br />
signal<strong>in</strong>g)<br />
� Antenna port 5 beamform<strong>in</strong>g, UE specific reference<br />
signals<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
10
Cyclic (Large) Delay Diversity<br />
(CDD)<br />
x 0<br />
x 0<br />
τ 0<br />
τ 1<br />
τ 2<br />
τ 3<br />
„artificial“<br />
multipath<br />
small delay<br />
spread<br />
delay spread<br />
frequency<br />
“flat”<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
τ 1<br />
τ 2<br />
τ 3<br />
frequency<br />
selective<br />
11
TB 1<br />
TB 2<br />
Open-loop SM<br />
� Inferference „randomization“.<br />
� In s<strong>in</strong>gle layer transmission (TRI = 1) TD mode (Alamouti) is<br />
used.<br />
CR 1<br />
Turbo<br />
encoder<br />
CR 2<br />
Turbo<br />
encoder<br />
MS 1<br />
modulator<br />
MS 2<br />
modulator<br />
layer<br />
mapp<strong>in</strong>g<br />
2-MUX<br />
or<br />
1-MUX<br />
2-MUX<br />
or<br />
1-MUX<br />
� is matrix formed from permutation of vectors:<br />
L0<br />
L1<br />
L2<br />
L3<br />
DFT<br />
Matrix<br />
Cyclic<br />
Delay<br />
Matrix<br />
Precod<strong>in</strong>g<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
frame mapper<br />
frequency first, then<br />
OFDM symbol <strong>in</strong>dex<br />
� column permutation chang<strong>in</strong>g every k subcarriers <strong>in</strong> a pre-def<strong>in</strong>ed manner.<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Tx0<br />
Tx1<br />
Tx2<br />
Tx3<br />
IFFT<br />
IFFT<br />
IFFT<br />
IFFT<br />
12
encoded bit<br />
stream<br />
,b 3, b 2, b 1, b 0,...<br />
Spatial Diversity<br />
Space-Time-Cod<strong>in</strong>g: Alamouti<br />
Symbol<br />
modulator<br />
„MIMO“ equalizer/detector<br />
… s 1, s 0,...<br />
space-time<br />
encoder<br />
… s 1, s 0,...<br />
… s* 0, -s* 1,...<br />
… y 1, y 0,...<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
h 0<br />
h 1<br />
space-time<br />
decoder<br />
equivalent „MIMO“ channel<br />
y 0<br />
y* 1<br />
decoder<br />
13<br />
s 0<br />
s 1<br />
No CSI at<br />
the transmitter<br />
required!!!
port #0<br />
port #1<br />
port #2<br />
port #3<br />
Space-Frequency Transmit Diversity<br />
“Alamouti-zation”<br />
0<br />
S 7<br />
0<br />
S 6 *<br />
0<br />
S 6<br />
0<br />
-S 7 *<br />
0<br />
X<br />
0<br />
0<br />
subcarrier <strong>in</strong>dex<br />
S 5<br />
0<br />
S 4 *<br />
0<br />
S 4<br />
0<br />
-S 5 *<br />
0<br />
X<br />
0<br />
0<br />
0<br />
� S<strong>in</strong>gle CW transmission, i.e s<strong>in</strong>gle MCS.<br />
0<br />
S 3<br />
0<br />
S 2 *<br />
0<br />
S 2<br />
0<br />
-S 3 *<br />
� Simple receiver structure, no matrix <strong>in</strong>version required<br />
0<br />
X<br />
0<br />
0<br />
S 1<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
S 0<br />
X<br />
0 0 0<br />
S * -S *<br />
0 1 0<br />
0<br />
equalized<br />
symbol equivalent channel<br />
received<br />
vector<br />
rather feed un-scaled<br />
„equalized symbol“ and<br />
scal<strong>in</strong>g factor to soft<br />
demodulator than perform<br />
division at this po<strong>in</strong>t<br />
0<br />
0<br />
IFFT<br />
IFFT<br />
IFFT<br />
IFFT<br />
X reference signal<br />
0<br />
0<br />
S 1<br />
„zeros“ as reference<br />
signal place holder<br />
„zeros“ from<br />
orthogonal SF code<br />
data symbol<br />
14
(Symbol) error rate:<br />
Diversity ga<strong>in</strong>:<br />
Cod<strong>in</strong>g ga<strong>in</strong>:<br />
Diversity order<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
15
Multiplex<strong>in</strong>g – Diversity tradeoff<br />
<strong>LTE</strong> spatial diversity techniques achieve:<br />
� diversity order (Mt£Mr): � full diversity for 2Tx<br />
� half diversity for 4Tx<br />
� rate (m<strong>in</strong>(Mt , Mr)): � full rate only for s<strong>in</strong>gle antenna receiver<br />
� half rate for 2Tx and 2Rx<br />
� ¼ rate for 4Tx and 4Rx<br />
� In <strong>LTE</strong> orthogonal space frequency block codes (OSTBC) are<br />
used that allow simple receiver structures<br />
⇒Symbol by symbol detection rather than vector detection.<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
16
Cell-Edge Beamform<strong>in</strong>g<br />
LOS<br />
LOS LOS<br />
LOS<br />
cell-specific<br />
frequency shift<br />
� to improve coverage for cell-edge user.<br />
� to reduce <strong>in</strong>ter-and <strong>in</strong>tra-cell <strong>in</strong>terference.<br />
� rank-1 assumption (LOS).<br />
reduced signal<strong>in</strong>g overhead<br />
� eNB aquires statistical <strong>in</strong>formation, e.g.<br />
DoDs of co-channel users at cell-edge<br />
� eNB computes optimum beamformer weights<br />
for each user and applies them <strong>in</strong> the DL<br />
transmission, no codebook and subband<br />
restriction.<br />
� multiple users are served on overlapp<strong>in</strong>g<br />
resources (MU-MIMO)<br />
� beamformer weights are explicitly signaled<br />
us<strong>in</strong>g user specific RS.<br />
� UE “sees” equivalent SI channel.<br />
� dedicated RS of all users <strong>in</strong> a cell are<br />
transmitted on the same RE (<strong>in</strong>terference),<br />
UE correlates received signal with dedicated<br />
(RNTI-based) pseudo random sequence.<br />
� <strong>LTE</strong>-feature that is expected to not be<br />
supported at <strong>in</strong>itial network rollout.<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
17
Antenna port 5 downl<strong>in</strong>k beamform<strong>in</strong>g<br />
Space Division Multiple Access (SDMA)<br />
MU1<br />
Femtocell basestation<br />
FU1<br />
MU2<br />
FU2<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
MU3<br />
Macro<br />
basestation<br />
18
Beamformer design and signal<strong>in</strong>g<br />
Subject to<br />
QoS constra<strong>in</strong>t for<br />
femtocell user<br />
Maximum <strong>in</strong>terference<br />
constra<strong>in</strong>st for macrocell user<br />
� Beamformers can be implicitly signaled to the users of<br />
the cell us<strong>in</strong>g antenna port 5 reference signals.<br />
Problem: Uncerta<strong>in</strong>ties <strong>in</strong> the DL channels<br />
� UL-DL reciprocity (e.g. <strong>in</strong> TDD)<br />
� channel feedback (requires cooperation of base<br />
stations)<br />
� Paramterer estimation, L<strong>in</strong>e-Of-Sight<br />
Robust designs wrt. channel mismatch can be used.<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
19
CQI report and 4-bit CQI table<br />
CQI<br />
<strong>in</strong>dex<br />
subband CQI <strong>in</strong>dex =differential CQI + wideband CQI <strong>in</strong>dex<br />
modulation code<br />
rate x<br />
1024<br />
0 out of range<br />
efficiency<br />
1 QPSK 78 0.1523<br />
2 QPSK 120 0.2344<br />
3 QPSK 193 0.3770<br />
4 QPSK 308 0.6016<br />
5 QPSK 449 0.8770<br />
6 QPSK 602 1.1758<br />
7 16QAM 378 1.4766<br />
8 16QAM 490 1.9141<br />
9 16QAM 616 2.4063<br />
10 64QAM 466 2.7305<br />
11 64QAM 567 3.3223<br />
12 64QAM 666 3.9023<br />
13 64QAM 772 4.5234<br />
14 64QAM 873 5.1152<br />
15 64QAM 948 5.5547<br />
2-bit subband differential CQI<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Differential CQI value Offset level<br />
0 ≤1<br />
1 2<br />
2 3<br />
3 ≥4<br />
3-bit subband/wideband<br />
spatial differential CQI<br />
Spatial differential CQI<br />
value<br />
20<br />
Offset level<br />
0 0<br />
1 1<br />
2 2<br />
3 ≥3<br />
4 ≤-4<br />
5 -3<br />
6 -2<br />
7 -1
MCS<br />
Index<br />
Adaptive cod<strong>in</strong>g and modulation<br />
<strong>in</strong> DL grant<br />
Modul<br />
ation<br />
Order<br />
TBS<br />
Index<br />
TBS for<br />
1 RB<br />
1layer<br />
…<br />
TBS for<br />
110 RBs<br />
1layer<br />
0 2 0 16 … 3112<br />
1 2 1 24 … 4008<br />
2 2 2 32 … 4968<br />
3 2 3 40 … 6456<br />
4 2 4 56 … 7992<br />
5 2 5 72 … 9528<br />
6 2 6 328 … 11448<br />
7 2 7 104 … 13536<br />
8 2 8 120 … 15264<br />
9 2 9 136 … 17568<br />
10 4 9 136 … 17568<br />
11 4 10 144 … 19080<br />
12 4 11 176 … 22152<br />
13 4 12 208 … 25456<br />
14 4 13 224 … 28336<br />
15 4 14 256 … 31704<br />
16 4 15 280 … 34008<br />
17 6 15 280 … 34008<br />
18 6 16 328 … 35160<br />
19 6 17 336 … 39232<br />
20 6 18 376 … 43816<br />
21 6 19 408 … 46888<br />
22 6 20 440 … 51024<br />
23 6 21 488 … 55056<br />
24 6 22 520 … 59256<br />
25 6 23 552 … 63776<br />
26 6 24 584 … 66592<br />
27 6 25 616 … 71112<br />
28 6 26 712 … 75376<br />
29 2<br />
30 4<br />
31 6<br />
reserve<br />
d<br />
reserved … reserved<br />
for code rate approx 1<br />
<strong>LTE</strong> target!!!<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Tdoc R1-07CQI_NNSN01<br />
21
SINR to CQI conversion<br />
for MMSE detector<br />
4 x 4 MIMO, full-rank<br />
MMSE estimate of SINR correspond<strong>in</strong>g to layer p and PMI i<br />
subcarrier<br />
PMI<br />
layer<br />
(column <strong>in</strong> PM)<br />
for subcarrier k , precod<strong>in</strong>g <strong>in</strong>dex i,<br />
and precod<strong>in</strong>g matrix P i<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
22
Average (effective) SINR<br />
Estimate for CW 0 (corresponds to averag<strong>in</strong>g over layer 1 and 2)<br />
Weight<strong>in</strong>g function for average SINR computation (based on rate)<br />
General: averag<strong>in</strong>g over layer, subcarriers,…<br />
SINR(N)<br />
SINI(N-1)<br />
SINR(N-2)<br />
SINR(N-3)<br />
SINR(4)<br />
SINR(3)<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
SINR(2)<br />
SINR(1)<br />
23
MIMO transmission modes<br />
Transmission mode Transmission scheme of PDSCH<br />
1 S<strong>in</strong>gle-antenna port, port 0<br />
2 Transmit diversity<br />
3 Transmit diversity if the associated<br />
rank <strong>in</strong>dicator is 1, otherwise large<br />
delay CDD<br />
4 Closed-loop spatial multiplex<strong>in</strong>g<br />
5 Multi-user MIMO<br />
6 Closed-loop spatial multiplex<strong>in</strong>g with a<br />
s<strong>in</strong>gle transmission layer<br />
7 If the number of PBCH antenna ports<br />
is one, S<strong>in</strong>gle-antenna port, port 0;<br />
otherwise Transmit diversity<br />
open-loop,<br />
no-PMI<br />
feedback<br />
closed-loop,<br />
with PMI<br />
feedback<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
24
PUSCH CQI: aperiodic<br />
Feedback Type<br />
Transmission mode 1 : Modes 2-0, 3-0<br />
Transmission mode 2 : Modes 2-0, 3-0<br />
Transmission mode 3 : Modes 2-0, 3-0<br />
Transmission mode 4 : Modes 1-2, 2-2, 3-1<br />
Transmission mode 5 : Mode 3-1<br />
Transmission mode 6 : Modes 1-2, 2-2, 3-1<br />
Transmission mode 7 : Modes 2-0, 3-0<br />
PUCCH CQI: periodic<br />
Feedback Type<br />
Transmission mode 1 : Modes 1-0, 2-0<br />
Transmission mode 2 : Modes 1-0, 2-0<br />
Transmission mode 3 : Modes 1-0, 2-0<br />
Transmission mode 4 : Modes 1-1, 2-1<br />
Transmission mode 5 : Modes 1-1, 2-1<br />
Transmission mode 6 : Modes 1-1, 2-1<br />
Transmission mode 7 : Modes 1-0, 2-0<br />
CQI report<strong>in</strong>g modes<br />
No PMI S<strong>in</strong>gle PMI Multiple PMI<br />
Wideband<br />
(wideband CQI) Mode 1-2<br />
UE Selected<br />
(subband CQI) Mode 2-0 Mode 2-2<br />
Higher Layerconfigured<br />
(suband CQI) Mode 3-0 Mode 3-1<br />
PMI Feedback Type<br />
No PMI S<strong>in</strong>gle PMI<br />
Wideband Mode 1-0 Mode 1-1<br />
(wideband CQI)<br />
UE Selected Mode 2-0 Mode 2-1<br />
(subband CQI)<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
25
Frequency (subbands)<br />
SINR<br />
Higher layer configured report<strong>in</strong>g<br />
modes: aperidodic report<strong>in</strong>g<br />
SINR(1)<br />
SINR(2)<br />
SINR(3)<br />
SINR(N-3)<br />
SINR(4)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
mode 3-0<br />
s<strong>in</strong>gle antenna, port 5<br />
TD and open-loop SM<br />
∆CQI(1)<br />
∆CQI(2)<br />
∆CQI(3)<br />
∆CQI(4)<br />
∆CQI(N-3)<br />
∆CQI(N-2)<br />
∆CQI(N-1)<br />
∆CQI(N)<br />
CQI(wideband)<br />
#bits 2N 4<br />
Frequency (subbands)<br />
mode 3-1<br />
closed-loop SM<br />
∆CQI(1)<br />
∆CQI(2)<br />
∆CQI(3)<br />
∆CQI(4)<br />
∆CQI(N-3)<br />
∆CQI(N-2)<br />
∆CQI(N-1)<br />
∆CQI(N)<br />
CW 0 CW 1<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
CQI(wideband)<br />
∆CQI(1)<br />
∆CQI(2)<br />
∆CQI(3)<br />
∆CQI(4)<br />
∆CQI(N-3)<br />
∆CQI(N-2)<br />
∆CQI(N-1)<br />
∆CQI(N)<br />
CQI(wideband)<br />
PMI(wideband)<br />
#bits 2N 4 2N 4 2|1|4<br />
+Rank Indicator (RI)<br />
26
UE selected report<strong>in</strong>g: mode 2-0 for<br />
s<strong>in</strong>gle antenna, port 5, TD and open<br />
loop SM: aperiodic report<strong>in</strong>g<br />
report # of bits<br />
bitmap of<br />
prefered M<br />
subband<br />
locations<br />
wideband<br />
CQI<br />
subband<br />
∆CQI<br />
4<br />
2<br />
SINR<br />
L CQI(N-1)<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
SINR(1)<br />
CQI(1)<br />
SINI(2)<br />
CQI(2)<br />
SINR(3)<br />
CQI(3)<br />
SINR(4)<br />
Frequency (subbands)<br />
CQI(4)<br />
measurements<br />
SINR(N-3)<br />
CQI(N-3)<br />
CQI(wideband)<br />
SINR(N-2)<br />
CQI(N-2)<br />
∆average CQI(selected subbands)<br />
SINR(N-1)<br />
27<br />
SINR(N)<br />
CQI(N)
Frequency (subbands)<br />
UE selected report<strong>in</strong>g: mode 2-2 for<br />
closed-loop SM: aperidodic report<strong>in</strong>g<br />
SINR(1)<br />
SINR(2)<br />
SINR(3)<br />
SINR(N-3)<br />
SINR(4)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
CW 0 CW 1<br />
CQI(1)<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
SINR(1)<br />
SINR(2)<br />
SINR SINR<br />
measurements per PMI required !!!<br />
SINR(3)<br />
SINR(4)<br />
SINI(N-3)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
CQI(1)<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
CQI(1)<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
report location of<br />
preferred<br />
subbands<br />
subband<br />
CQI<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
28<br />
subband<br />
CQI<br />
#bits L 4|2|8 4 2 4 2<br />
select best PMI and subands<br />
(<strong>in</strong> terms of comb<strong>in</strong>ed data rate)<br />
PMI<br />
CQI(wideband)<br />
CW 0 CW 1<br />
∆average CQI(selected subbands)<br />
CQI(wideband)<br />
∆average CQI(selected subbands)<br />
+Rank Indicator (RI)
Frequency (subbands)<br />
mode 1-2<br />
closed-loop SM<br />
CW0 CW1<br />
CQI(wideband)<br />
CQI(wideband)<br />
#bits 4 4 2N| N|4N<br />
Wideband CQI report<strong>in</strong>g<br />
modes: aperidodic report<strong>in</strong>g<br />
PMI(1)<br />
PMI(2)<br />
PMI(3)<br />
PMI(4)<br />
PMI(N-3)<br />
PMI(N-2)<br />
PMI(N-1)<br />
PMI(N)<br />
SINR(1)<br />
SINR(2)<br />
SINR(3)<br />
SINR(N-3)<br />
SINR(4)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
SINR<br />
+Rank Indicator (RI)<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
29
Frequency (subbands)<br />
Higher layer configured report<strong>in</strong>g<br />
modes for perdiodic feedback:<br />
perdiodic report<strong>in</strong>g<br />
CQI(wideband)<br />
#bits 4<br />
mode 1-0<br />
s<strong>in</strong>gle antenna port,<br />
open-loop SM, TD<br />
CW 0<br />
Frequency (subbands)<br />
mode 1-1 (rank 1)<br />
closed-loop SM, MU-MIMO<br />
CW 0<br />
CQI(wideband)<br />
PMI(wideband)<br />
#bits 4 2|1|4<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Frequency (subbands)<br />
+Rank<br />
Indicator<br />
(RI)<br />
mode 1-1 (rank 2)<br />
closed-loop SM, MU-MIMO<br />
CW 0 CW 1<br />
CQI(wideband)<br />
differential spatial CQI(wideband)<br />
30<br />
PMI(wideband)<br />
#bits 4 3 2|1|4
UE selected report<strong>in</strong>g: mode 2-0 for<br />
s<strong>in</strong>gle antenna, port 5, TD and open<br />
loop SM: periodic report<strong>in</strong>g<br />
report # of bits<br />
bitmap of prefered M<br />
subband locations for<br />
current bandwidth<br />
part<br />
wideband<br />
CQI<br />
subband<br />
CQI<br />
DL<br />
⎡log2 ⎡N RB / k J ⎤⎤<br />
L =<br />
/<br />
L<br />
4<br />
4<br />
SINR<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
SINR(1)<br />
CQI(1)<br />
SINI(2)<br />
Frequency (subbands)<br />
CQI(2)<br />
SINR(3)<br />
CQI(3)<br />
SINR(4)<br />
CQI(4)<br />
measurements<br />
CQI(wideband)<br />
SINR(N-3)<br />
CQI(N-3)<br />
CQI(selected subbands)<br />
SINR(N-2)<br />
CQI(N-2)<br />
SINR(N-1)<br />
CQI(N-1)<br />
N 1 N 2 N<br />
J<br />
SINR(N)<br />
CQI(N)<br />
31
Frequency (subbands)<br />
DL<br />
⎡log2 ⎡N RB / k J ⎤⎤<br />
L =<br />
/<br />
UE selected report<strong>in</strong>g:<br />
mode 2-1for closed-loop SM:<br />
periodic report<strong>in</strong>g<br />
CW 0 CW 1<br />
CQI(1)<br />
SINR(1) CQI(1)<br />
SINR(1)<br />
SINR(2)<br />
SINR(3)<br />
SINR(N-3)<br />
SINR(4)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
measurements per PMI !!!<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
SINR(2)<br />
SINR(3)<br />
SINR(4)<br />
SINI(N-3)<br />
SINR(N-2)<br />
SINI(N-1)<br />
SINR(N)<br />
SINR SINR<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
report<br />
select best PMI and subands<br />
(<strong>in</strong> terms of comb<strong>in</strong>ed data rate)<br />
CQI(1)<br />
CQI(2)<br />
CQI(3)<br />
CQI(4)<br />
CQI(N-3)<br />
CQI(N-2)<br />
CQI(N-1)<br />
CQI(N)<br />
location of<br />
preferred<br />
subbands <strong>in</strong><br />
Bandwidth part j<br />
CW 0<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
subband<br />
CQI<br />
32<br />
subband<br />
CQI<br />
#bits L 2|1|4 4 4 3 3<br />
k = subband size<br />
J = number of bandwidth parts (see also next slide) +Rank Indicator (RI)<br />
N 1<br />
N J<br />
PMI<br />
CQI(wideband)<br />
CQI(selected subbands)<br />
differential spatial CQI(wideband)<br />
CW 1<br />
differential CQI(selected subbands)
Report tim<strong>in</strong>g configuration for<br />
mode 2-1: periodic report<strong>in</strong>g<br />
M RI = 2: RI report<strong>in</strong>g periodicity with respect to WB report<strong>in</strong>g periodicity<br />
RI<br />
N P = 2: Report<strong>in</strong>g Periodicity <strong>in</strong> TTIs<br />
J = 3: SB bitmap-report is split <strong>in</strong>to J bandwidth parts that are reported <strong>in</strong> consecutive <strong>in</strong>tervals<br />
K = 2: SB report<strong>in</strong>g periodicity (J consecutive SB reports) with respect to WB report<strong>in</strong>g periodicity<br />
SB<br />
CQI<br />
j = 0<br />
WB<br />
CQI<br />
SB<br />
CQI<br />
j= 1<br />
SB<br />
CQI<br />
j = 0<br />
SB<br />
CQI<br />
j = 2<br />
report<br />
SB<br />
CQI<br />
j= 1<br />
RI<br />
SB<br />
CQI<br />
j = 2<br />
SB<br />
CQI<br />
j = 0<br />
…cont<strong>in</strong>ue…<br />
WB<br />
CQI<br />
location of preferred<br />
subbands <strong>in</strong><br />
Bandwidth part j<br />
SB<br />
CQI<br />
j = 0<br />
SB<br />
CQI<br />
j= 1<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
PMI<br />
SB<br />
CQI<br />
j= 1<br />
SB<br />
CQI<br />
j = 2<br />
WB<br />
CQI<br />
CW1<br />
SB<br />
CQI<br />
j = 2<br />
WB<br />
CQI<br />
subband<br />
CQI<br />
SB<br />
CQI<br />
j = 0<br />
WB<br />
CQI<br />
CW2<br />
SB<br />
CQI<br />
j = 0<br />
#bits L 2|1|4 4 4 3 3<br />
SB<br />
CQI<br />
j= 1<br />
subband<br />
CQI<br />
SB<br />
CQI<br />
j= 1<br />
SB<br />
CQI<br />
j = 2<br />
33<br />
SB<br />
CQI<br />
j = 2<br />
WB<br />
CQI
Multi-User DL MIMO<br />
� MAC scheduler decides on users<br />
„pair<strong>in</strong>g“<br />
� Maximum 2 users on same resource<br />
due to 2TB restriction<br />
mode 3-1<br />
closed-loop SM<br />
CW 0 CW 1<br />
∆CQI(1) ∆CQI(1)<br />
∆CQI(2)<br />
∆CQI(3)<br />
∆CQI(4)<br />
∆CQI(N-3)<br />
∆CQI(N-2)<br />
∆CQI(N-1)<br />
∆CQI(N)<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
Frequency (subbands)<br />
CQI(wideband)<br />
∆CQI(2)<br />
∆CQI(3)<br />
∆CQI(4)<br />
∆CQI(N-3)<br />
∆CQI(N-2)<br />
∆CQI(N-1)<br />
∆CQI(N)<br />
CQI(wideband)<br />
34<br />
PMI(wideband)<br />
#bits 2N 4 2N 4 2|1|4
Multi-User DL MIMO<br />
UE 1<br />
UE 1<br />
UE 2<br />
UE 2<br />
for<br />
UE 1<br />
for<br />
UE 2<br />
channel „experienced“ at user 1<br />
desired <strong>in</strong>terfer<strong>in</strong>g<br />
4<br />
channel „experienced“ at user 2<br />
<strong>in</strong>terfer<strong>in</strong>g desired<br />
No jo<strong>in</strong>t process<strong>in</strong>g at Rx, no cooperation!<br />
Pre-cod<strong>in</strong>g matrix selection (UE1) maximize<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
2<br />
2<br />
2<br />
2<br />
4<br />
4<br />
4<br />
4<br />
2<br />
m<strong>in</strong>imize<br />
35
UL-MIMO<br />
� UL-MIMO is not explicitly supported <strong>in</strong> <strong>LTE</strong>,<br />
� s<strong>in</strong>gle antenna port <strong>in</strong> UL, no s<strong>in</strong>gleuser(SU)<br />
SM <strong>in</strong> UL<br />
� demodulation UL reference signals (DRS)<br />
of different users overlap/<strong>in</strong>terfere<br />
� DRS of different users are separated <strong>in</strong> TD<br />
accord<strong>in</strong>g to „cyclic-shift“ of identical sequence<br />
(theoretical max. of 8 user, depend<strong>in</strong>g on delayspread)<br />
� depends on eNB scheduler‘s flexibility and PHY<br />
support<br />
r* PUSCH (k)<br />
„cyclic-shift“ zero<br />
FFT DRS demapper x<br />
h 1[t] h 2[t] h 3[t] h 12[t]<br />
delay spread max 12 cyclic shift<br />
IFFT<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
h 1[t]+ h 2[t]+…+ h 12[t]<br />
36
Spectral efficiency<br />
3GPP self-evaluation results<br />
Source: 3GPP self evaluation results, 3GPP TSG-RAN chair, oct 2009<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
37
Throughput [Bits]<br />
<strong>LTE</strong> DL simulation results reported<br />
by the Top4 lead<strong>in</strong>g <strong>LTE</strong> vendors<br />
14000000<br />
12000000<br />
10000000<br />
8000000<br />
6000000<br />
4000000<br />
2000000<br />
0<br />
-10 -5 0 5 10 15 20<br />
SNR <strong>in</strong> dB<br />
16QAM 1/2 EVA5 50 RB 2x2 SFBC<br />
1<br />
2<br />
mimoOn<br />
3<br />
4<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
38
<strong>LTE</strong>-<strong>Advanced</strong>: Concepts<br />
� Improved Spectrum Flexibility<br />
� Bandwidth up to 100MHz<br />
� Spectrum and carrier aggregation<br />
� MIMO<br />
� support SM <strong>in</strong> UL<br />
� Higher order MIMO <strong>in</strong> DL<br />
� Coord<strong>in</strong>ated Multipo<strong>in</strong>t Transmission<br />
from <strong>in</strong>terference randomization to<br />
<strong>in</strong>terference coord<strong>in</strong>ation<br />
� Multihop Relays<br />
� L1 repeaters to improve coverage<br />
� L3 relays for self-backhaul<strong>in</strong>g eNB<br />
100 MHz<br />
20 MHz 20 MHz<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
eNB<br />
relay<br />
node<br />
39<br />
UE
<strong>LTE</strong>-<strong>Advanced</strong><br />
advanced MIMO receiver structure<br />
SD-SIC for OFDMA<br />
Y<br />
Y<br />
Y<br />
Y<br />
k , 1<br />
k , 2<br />
k , 3<br />
k , 4<br />
LMMSE / Soft IC<br />
Channel estimate<br />
S/P<br />
S/P<br />
Channel estimate<br />
LLR calc.<br />
LLR calc.<br />
2 codewords used,<br />
each S/P-mapped onto 2 Tx antennas<br />
Signal<br />
construction<br />
Rate<br />
match<strong>in</strong>g<br />
Rate<br />
match<strong>in</strong>g<br />
Signal<br />
construction<br />
Decoder<br />
Decoder<br />
Figure: NSN: R1-083732 / 2008-09-23<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
40
End of Part 2<br />
Thank you!!!<br />
Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Read<strong>in</strong>g, UK © mimoOn<br />
41
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