Proposal for Radio Resource Allocation using Dummy Burst Definition in IEEE 802.16 Uplinks

Proposal for Radio Resource Allocation using Dummy Burst Definition in IEEE 802.16 Uplinks

Takeo Ohseki and Takashi Inoue

Radio Access Laboratory, KDDI R&D Laboratories, Inc.

Ohara 2-1-15, Fujimino, Saitama, 356-8502, JAPAN

WCNC 2008

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Outline

Introduction IEEE 802.16 Systems Dummy Burst and Radio Resource Allocation

Method Considering Inter-cell Interference Numerical Analysis Conclusion

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Introduction

OFDMA is particularly anticipated in next-generation mobile networks multipath environments providing higher throughput and capacity considerable flexibility in managing spectrum

resources improved coverage

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Introduction

Uplinks of IEEE 802.16 OFDMA

PUSC

In PUSC mode Each subchannel, which consists of several sub

carriers, is allocated to a single user

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Introduction

BS allocates the uplink resource UL burst UL-MAP

The allocation of subchannels to users cannot be conducted flexibly without generating blank logical subchannels

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IEEE 802.16 SystemsA. OFDMA uplink subframe structure in IEEE 802.16

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IEEE 802.16 Systems B. OFDMA uplink subchannel permutation in IEEE 802.16

-Tiles(s, n) is the physical tile index in the FFT with tiles being ordered consecutively

-s is the subchannel number in the range 0 . . . Nsubchannels − 1

-n is the tile index 0 . . . 5 in a subchannel

-UL_PermBase is an integer value in the range 0 . . . 69

-Pt(·) is the tile permutation

-index(·, x) denotes the function that returns the x-th element

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceA. Introduction of Dummy Burst

In uplinks in the IEEE 802.16 system, data are initially allocated in bursts built on logical subchannels

A permutation of the tiles within a subchannel map tiles to physical subchannels

If there are some logical subchannels in a bad radio propagation environment, the bursts cannot avoid them

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceA. Introduction of Dummy Burst

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceB. Radio Resource Allocation using Dummy Burst

As regards interference between cells UL_PermBase

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceB. Radio Resource Allocation using Dummy Burst

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceB. Radio Resource Allocation using Dummy Burst

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceC. Requirements for realization

1) About changing UL_PermBase:

UL PermBase must be changed depending on traffic

In the IEEE 802.16 systems, A control message called Zone IE The dynamic change in the UL_PermBase can be reali

zed with the message transmitted by the BS

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceC. Requirements for realization

2) Concerning traffic detection:

The centralized control station to control multiple BSs is assumed

All the BSs regularly notify the centralized control station of the logical subchannels that they use.

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Dummy Burst and Radio Resource Allocation Method Considering Inter-cell InterferenceC. Requirements for realization

3) About a default value of UL PermBase:

When dummy bursts are inserted The same value of UL PermBase must be used betwe

en interfering cells

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Numerical AnalysisA. Ratio of interfering tiles

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Numerical AnalysisA. Ratio of interfering tiles

UL_Permbase = 0BS0

BS1

(BS1)

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Numerical AnalysisB. Throughput Performance

UL_Permbase = 0BS0

BS1

UL_Permbase = 2

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Numerical AnalysisB. Throughput Performance

proposed method

Subchannel<30

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Numerical AnalysisC. Discussion

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Conclusion

The authors proposed a novel concept for the definition of bursts in IEEE 802.16 uplinks Generating blank logical subchannels between used logical s

ubchannels in uplinks A radio resource allocation scheme successfully avoiding inte

rference between the cells based

Numerical analysis confirmed that Throughput performance can improve