Control Channel Design Requirements
Document Number: IEEE C80216m-09_0021r1
Date Submitted: 2009-01-12
Source:
Kiran Kuchi, J. Klutto Milleth, Vinod R, Dileep M K,
Divagar , Padmanabhan M S,
Bhaskar R, Giridhar K
Voice:
CEWiT, India
E-mail:
[email protected],
[email protected]
Venue:
San Diego, USA. In response to the TGm Call for Contributions and Comments IEEE 802.16m-08/052 for
Session 59
Topic TGm SDD - section 11.7.2 (Transmission of DL control )
Base Contribution: IEEE C80216m-09_0021
Purpose: Presentation associated with comment tgmsdd_Kuchi_Kiran.cmtb associated with section 11.7.2 in
SDD
To discuss in TGm for appropriate action. Notice:
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Presentation Outline


Design requirements for common control
channels such as SBCH, DL-MAP, etc.
Performance comparison


Noise and interference limited scenarios
Conclusions
7/29/2017
2
Common Control Channel Requirements



We consider design requirements for common control channels e.g, SBCH,
DL-MAP etc.
Control channel should transmit the system information reliably to the users
at least SINR
According to S802.16m-08_1420r1, the target SINR[dB] against the cell
range and SINR Coverage
Cell range
0.87 Km
5 Km
95.00%
-3.7
-5.5
97.00%
-4
-6
98.00%
-4.5
-6.5
Simulation Assumptions


Antenna Schemes

2 x 2 SFBC

2 x 2 POD

4 x 2 SFBC

4 x 2 SFBC + POD (a.k.a SFBC+rank-1 precoding)
Simulation Parameters
– Number of information bits: 48
– Modulation and Coding: QPSK ½ CTC with variable repetition
– Channel Model: eITU PED-B
– Channel estimation: PRU based MMSE
– Resource: distributed PRU
– MIMO receiver: MMSE
Link Level Performance Evaluation in Noise
Limited Case
2 x 2 Antenna schemes
POD and SFBC have comparable performance
4 x 2 Antenna schemes
POD and SFBC have comparable performance
Link Level Performance Evaluation in Interference
Limited Case
Evaluation of CDR and Conventional Bit-Repetition for the
Transmission of Control Channels

Evaluated Schemes and Simulation setups

802.16e type bit repetition scheme



Pilot on data, 5dB pilot boosting, PRBS ,12 pilots per RB

MF receiver
Conjugate data repetition (CDR) combined with bit level repetition

Pilot on Pilot,PRBS,12 pilots per RB

MMSE receiver
Conjugate data repetition with orthogonal pilots

Pilot on Pilot, Orthogonal sequence,16 pilots per RB

MMSE receiver
Simulation Assumptions

Antenna scheme : 4 x 2, POD

Resource : Distributed LRU

Channel Model : eITU PED-B

Interference Profile


Typical reuse-1 C/I profile = [0 3 6 9 12 14 14 15] ==> -2.75dB

Typical reuse-1 Cell edge C/I profile=[0 0.6 2 3.4 4.6 6.7 8.3] ==> -5.5dB

The profile consists of Signal to Interference Power Ratio up to 8-dominant interferers in
ascending order
BLER is evaluated as a function of SRIR which is defined as:
SRIR= Signal Power/(Noise+Residual interference power excluding the dominant 8-interferers)
*In interference limited networks, operating SRIR is usually in 12-15 dB range
SINR= Signal Power/(Noise+Total interference power)

Channel Estimation – 2DMMSE within RB (PRU)
Typical reuse-1 Interference Profile
Typical reuse-1 cell edge interference profile
System Level Performance
Evaluation
System Level Simulation for Cell Edge Users
CDF of BLER for ½ QPSK with repetition factor =4
BLER of CDR < 0.1 for 96% of users
•BLER of conventional system is < 0.1 for 48% users
•Doubles the control channel coverage
•
System Level Simulation for Cell Edge Users
CDF of BLER for ½ QPSK with repetition factor =6
BLER of CDR < 0.05 for 98% of users
•BLER of conventional system is < 0.05 for 40% users
•The gain in control channel coverage is significant
•
Conclusions

MIMO mode for control channels

Minimum 8 repetitions are required to achieve cell coverage for 0.87km radius cell and More than 8
repetitions are required for 5km radius cell

In white noise, POD and SFBC+POD perform equally well with 8 repetitions

POD outperforms SFBC+POD with interference suppression receivers



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SFBC uses 6-pilots/antenna, POD can use up to 16-pilots
POD with 16-pilots/RB supports orthogonal pilots whereas SFBC with 6-pilots/ant does not
support orthogonal pilot allocation
Suggest “Rank-1 precoding (POD) with repetition 8 for common control channels”
CDR vs Conventional bit repetition

CDR outperforms conventional bit repetition for all the interference profiles

The reduction in BLER is quite significant
Pilot Selection

Pilot on pilot is preferred for CDR

Orthogonal pilots give significant gain over PRBS

16 Pilots per RB + orthogonal pilot sequence + pilot planning is suggested