Resource Management in WCDMA - Multiobjective Optimization Methodology: A Jumping Gene Approach - page 150

It. is. known. that. if. the. assigned. transmission. power. of. a. particular. user.
is. too. high,. it. will. lower. the. service. quality. of. the. others.. A. similar. result.
applies.to.the.user's.transmission.rate..If.one's.transmission.rate.is.too.high,.
one's.QoS.may.be.easily.violated..Thus,.by.adjusting.the.transmission.power.
and.transmission.rate.of.users,.the. / 0 E b .value.of.a.QoS-violating.user.can.

be. improved,. resulting. in. better. QoS.. In. addition,. having. the. / 0

E b . value.
of.a.QoS-satisfying.user.close.to.γ.can.eventually.improve.the.QoS.of.other.
users.. Thus,. it. is. desirable. that. each. user. adopt. a. sufficient. transmission.
power.and.transmission.rate.so.that.the.QoS.is.satisfied.
Assume.that.no.users.end.their.calls,.and.no.idle.users.initiate.a.new.
call. at. a. particular. moment;. resource. management. can. reallocate. the.
excessive.resources.consumed.by.QoS-satisfying.users.to.QoS-violating.
users.. Furthermore,. this. can. also. provide. sufficient. resources. for. users.
who. connect. in. the. future. if. the. maximum. capacity. has. not. yet. been.
reached.
In.this.study,.a.centralized.resource.management.in.direct.sequence.wide-
band.code.division.multiple.access.(DS-WCDMA).systems.was.considered..
Its.implementation.steps.were.as.follows:.At.the.beginning.of.a.time.slot,.the.
resource. management. center. received. the. data. from. the. database,. includ-
ing. the. measured. link. gain,. the. requested. media. type,. and. the. identifica-
tion.number.of.the.assigned.base.station.of.each.connecting.user..With.these.
data,.the.center.performed.an.optimization.technique.to.determine.the.opti-
mized. transmission. power. and. transmission. rate. of. each. connecting. user.
within.the.maximum.allowable.computation.time..Finally,.each.base.station.
received.the.corresponding.values.for.the.transmission.power.and.transmis-
sion.rate.of.its.connecting.mobile.phones.from.the.center.and.instructed.each.
phone.to.apply.the.values.by.sending.a.command.through.its.communica-
tion.channel.
Note. that. the. total. transmission. power. and. the. total. transmission. rate.
were.competing.with.each.other..Therefore,.the.problem.was.a.multiobjec-
tive.optimization.problem.

7.2 MathematicalFormulation
In. this. section,. an. optimization. problem. is. formulated. so. that. resources,.
including. transmission. powers. and. transmission. rates,. are. optimally. allo-
cated. to. all. connecting. users. [2].. The. objectives. are. to. minimize. the. total.
transmission. power. and. maximize. the. total. transmission. rate. of. all. users.
simultaneously.. However,. optimization. of. these. two. objectives. may. easily.
lead. to.solutions. with. a.large. number. of.users. violating.the.QoS.. Thus,.an.
alternative. method. is. sought.. The. problem. is. reformulated. by. introducing.