1. 2.5msec Frame structure for Mobility performance improvement
Runcom
Peretz Shekalim, Zion Hadad
November 12, 2007
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2. Objective 2.5msec Frame structure (one preamble only every 2.5 msec).
2.5msec Frame structure for TDD/FDD/H-FDD
For the TDD, Similar Frame Structure as 5 msec
For the H-FDD MS population can be divided into 2 logical groups within each 2.5msec frame.
1 preamble per each 2.5msec frame, with MAP and Sub map considered for the first DL group, and MAP or SubMap for the second DL group
No UL traffic when preamble is transmitted
Group 2 can have UL traffic when group 1 is transmitting in DL
Dynamic DL/UL structure for H-FDD
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3. 2.5msec frame structure for TDD/FDD/HFDDDL UL DL UL
TDD
FDD F1 DL DL UL UL
FDD F2
1.25 (or <2.5) ms
1.25 (or <2.5) ms
1.25 (or <2.5) ms
1.25 (or <2.5) ms
Group DL 1
Group DL 2
Group DL 1
Group DL 2
H-FDD F1
H-FDD F2
Group UL 2
Group UL 1
Group UL 2
Group UL 1
SSRTG
SSTTG
SSRTG
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4. Faster response to the current Channel conditions:
Advantage of 2.5msec frame duration in compare to 5msec frame duration (1 of 2)
Faster response to the current Channel conditions:
Improvement of the Open Loop, Closed Loop MIMO/Sounding  Higher mobility.
Optimized MCS management.
Performance improvement of the Closed Loop Power Control,
Decrease PDU Error Rate (Faster Adjustment according to the current Channel conditions – MCS, Tx).
Smaller Fade Margin (at least 3dB for Mobile UTs)  Expansion of cell coverage and cell capacity.
Decreasing of the HO processing time more than 50% (transaction time decrease to 50%, and less Jitter due to the shorter frame size).
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5. Performance improvement of the ARQ and HARQ.
Advantage of 2.5msec frame duration in compare to 5msec frame duration (2 of 2)
Performance improvement of the ARQ and HARQ.
QoS improvement due to shorter delay (Signaling, Messages, allocations, etc.).
Performance improvement of the time dependent application protocols (TCP).
Less Jitter, improved capacity (more Erlangs)  higher throughput/cell.
Decreasing of the Power consumption
Reduction of the implementation cost.
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6. Increase of MAP overhead
More overhead (< 8%) might be introduced by using the current DL/UP MAP structure in 5msec frame duration.
However, at least for the FDD or H-FDD systems here is no need for Backward compatibility as only TDD systems (BS & UT) already defined or implemented.
Furthermore, MAC part of the system is usually programmable, so upon using 2.5msec frames, the system can use strong MAP reduction solutions when available.
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