November 3, 2008
Why did ATT commit to Verizon choose to use LTE for new nationwide 700 Mhz spectrum? The answer is peak-to-average power ratio (PAPR), which is a measurement of a waveform, calculated from the peak amplitude of the waveform divided by the RMS (time-averaged) value of the waveform. In other words the amount of power needed to capture the signal.
Lots of people with lots of math will tell you that Frequency Division Multiplexing -[FDM] is a good way to carry the signal, but its the critical capture that drains the battery of the device. So the uplink is the issue. While the cellular industry has increased bit rates steadily, the 4G network represents a huge leap in delivery of the wireless Internet.
3GPP's adoption of Orthogonal Frequency Division Multiplexing [OFDM] as part of LTE, enables an easier migration from the legacy US networks. And while single carrier and OFDM are normally different strategies, SC-FMDA is the secret sauce in the migration path for us in North America.
I could bore you (and confuse myself) with all the math involved in understanding how SC-FDMA in effect lets you have your cake and eat it too, but the real story is the impact on the mindset of the carriers.
What this has done is put the landline carrier to the side. While we could make a case for the WiMAX Fixed Wireless being the next step for the ILECs, the LTE story is compelling enough to steal the thunder of the WIMAX solution for the US market.
As wall street turns up its nose on the CenturyTel, Embarq story, its clear that LTE is the best story in the US market. At least until after the regime change in January 09.
, 700 Mhz
: Related Tags: frequency division
, division multiplexing
Feedback for It Looks Good on PAPR.