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Proposal for Inter-cell Multiple Access Scheme in 802.16m Downlink Zhou Shidong, Li Yunzhou Tsinghua University.

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Presentation on theme: "Proposal for Inter-cell Multiple Access Scheme in 802.16m Downlink Zhou Shidong, Li Yunzhou Tsinghua University."— Presentation transcript:

1 Proposal for Inter-cell Multiple Access Scheme in m Downlink Zhou Shidong, Li Yunzhou Tsinghua University

2 Content Non-orthogonal downlink resource allocation among adjacent cells/sectors Requirement of resource allocation criterion

3 Physical resource allocation of downlink Multiuser resource allocation within each cell – Orthogonal allocation is highly recommended, i.e., OFDMA, both in time domain and frequency domain – In special cases, non-orthogonal allocation can also be included Superposition coding for making full use of near-far effect Multi-cell resource allocation between adjacent cells – Fractional frequency reuse can be applied – At the cell edge, when traffic is light, orthogonal allocation is highly recommended – At the cell edge, when traffic is heavy, non-orthogonal resource allocation (time/frequency reusing) among adjacent cells will be included, e.g., CDMA, IDMA (interleaver divistion multiple access)

4 Spectrum segmentation for downlink physical resource allocation at the cell edge Different resource blocks (chunks) can be allocated to adjacent cells A separate segment of resource blocks is to be assigned for the use of IDMA – This region can be further divided into subzones, for different kinds of resource reuse Benefit of IDMA – Provide more users served at cell edge – Provide higher data rate with joint decoding at cell edge.

5 Requirement on non-orthogonal resource allocation When only single-user-decoding is applied with IDMA, – no additional restriction of resource allocation When some of the terminals at cell edge need to perform joint decoding with adjacent cell users – Resource allocation alignment is recommended – For simple implementation With resource alignment, joint decoding can be local ones Without resource alignment, joint decoding should be global

6 Proposed SDD Text (1) x.x Downlink and Uplink Multiple Access Schemes – IEEE m uses OFDMA as the downlink intra- cell/sector multiple access scheme. – As for downlink inter-cell/sector multiple access schemes, besides orthogonal(time/frequency) multiple access among adjacent cells/sectors where cell/sector edge traffic is not very heavy, non-orthogonal multiple access shall be included for heavy traffic as cell/sector edge, when adjacent cells/sectors can use the same frequency/time resource simultaneously. – As an additional non-orthogonal multiple access technique, IDMA is used to support higher rate for users at cell/sector edge.

7 Proposed SDD Text (2) x.x Downlink Physical Resource Allocation Unit – When non-orthogonal downlink multiple access among adjacent cells/sectors is to be applied for downlink resource allocation, a segment for non- orthogonal resource allocation shall be defined, which is better to be aligned with adjacent cells/sectors. The allocation of such resource segment among users shall support resource unit alignment among users from adjacent cells/sectors which may share the resource.


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