How Wide A Wideband Channel Should Be?
[Frequency Selectivity of A 1.2288MHz, 3GPP2, TSG-C, Working Group 3, C30-20090511-028] How wide should a channel be before it is called wideband? Dictionary.com says it is " responding to or operating at a wide band of frequencies ". I guess this is pretty much the one in most people's mind. Wikipedia.org gives us a more technical definition," a system is typically described as wideband if the message bandwidth significantly exceeds the channel's coherence bandwidth ". Basically it says whether a channel can be called wideband channel or not largely depends on the multiple of coherence bandwidth it has. The question then becomes what is coherence bandwidth and how wide a typical coherence bandwidth can be. For example, should a CDMA2000 channel, which has a bandwidth of 1.22288MHz, be called wideband or not? Why can a 5.0MHz WCDMA channel usually be called wideband? Let's find out here. Coherence Bandwidth Coherence bandwidth is a statistica