光看这一段没人能看懂哦。你这是《WCDMA.for.UMTS》上的一段话。
是为了解释“为何目标SIR需要变化”。目标SIR是根据误码率/误块率设定的。同样的误码率,在不同的移动速度和多径环境下需要的SIR是不一样的。假设需要超过1%的误块率,在高速移动环境下就要比较高的SIR,如果手机进入低速还使用高速时的SIR,那么就意味着功率要大很多,会导致不必要的容量浪费。
Why should there be a need for changing the target SIR
setpoint? The
required SIR (there exists a proportional Eb=N0 requirement)
for, say, **ER ¼ 1% depends
on the mobile speed and the multipath profile.
Now, if one were to set the target SIR setpoint
for the worst case, i.e. high
mobile speeds, one would waste much capacity for those
connections at low
speeds. Thus, the best strategy is to let the target SIR setpoint
float
around the minimum value that just fulfils the required target
quality.