TY - JOUR

T1 - On the complexity of sequential rectangle placement in IEEE 802.16/WiMAX systems

AU - Israeli, Amos

AU - Rawitz, Dror

AU - Sharon, Oran

PY - 2008/11

Y1 - 2008/11

N2 - We study the problem of scheduling transmissions on the downlink of IEEE 802.16/WiMAX systems that use the OFDMA technology. These transmissions are scheduled using a matrix whose dimensions are frequency and time, where every matrix cell is a time slot on some carrier channel. The IEEE 802.16 standard mandates that: (i) every transmission occupies a rectangular set of cells, and (ii) transmissions must be scheduled according to a given order. We show that if the number of cells required by a transmission is not limited (up to the matrix size), the problem of maximizing matrix utilization is very hard to approximate. On the positive side we show that if the number of cells of every transmission is limited to some constant fraction of the matrix area, the problem can be approximated to within a constant factor. As far as we know this is the first paper that considers this sequential rectangle placement problem.

AB - We study the problem of scheduling transmissions on the downlink of IEEE 802.16/WiMAX systems that use the OFDMA technology. These transmissions are scheduled using a matrix whose dimensions are frequency and time, where every matrix cell is a time slot on some carrier channel. The IEEE 802.16 standard mandates that: (i) every transmission occupies a rectangular set of cells, and (ii) transmissions must be scheduled according to a given order. We show that if the number of cells required by a transmission is not limited (up to the matrix size), the problem of maximizing matrix utilization is very hard to approximate. On the positive side we show that if the number of cells of every transmission is limited to some constant fraction of the matrix area, the problem can be approximated to within a constant factor. As far as we know this is the first paper that considers this sequential rectangle placement problem.

KW - Approximation algorithms

KW - IEEE 802.16/WiMAX systems

KW - Scheduling

KW - Sequential rectangle placement

UR - http://www.scopus.com/inward/record.url?scp=53449102189&partnerID=8YFLogxK

U2 - 10.1016/j.ic.2008.07.002

DO - 10.1016/j.ic.2008.07.002

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AN - SCOPUS:53449102189

SN - 0890-5401

VL - 206

SP - 1334

EP - 1345

JO - Information and Computation

JF - Information and Computation

IS - 11

ER -