RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

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I agree that the guard bands should be included.

And probably we should add the "adjacent channel rejection" performance,

defined for 1dB of receive sensitivity level degradation.

You are correct that my intention is to define a way to evaluate spectral efficiency in a consistent manner.

In the case of cdma2000, the individual channels can be placed directly adjacent to one another but there

is still a required guard band on either end of these channels. For 1900 MHz systems, the guard band

on each end is typically 625 kHz, for a total of 1.25 MHz. Thus, for a single cdma2000 carrier the total

spectrum requirement is 0.625 kHz + 1.25 MHz + 0.625 kHz = 2.5 MHz. For 2 carriers, the total

spectrum requirement is 3.75 MHz and for 3 carriers the total is 5 MHz. As you noted, the requirement

may be less at 450 MHz but there is still a clear requirement for some guard bands and this would impact

the calculation of spectral efficiency.

For UMTS, the chip rate is 3.84 Mcps so the basic bandwidth requirement is commonly quoted as

3.84 MHz. This would be the -3 dB bandwidth or, rather, the equivalent noise bandwidth.

I do not know what you refer to in terms of modifications for the US PCS bands. The 3GPP standards

do include the definitions and specifications for the 5 MHz frequency blocks that are part of the bandplan

for the US PCS bands. The 3.84 Mcps carrier completely fits into the 5 MHz block since there is "extra"

space on either side.

The bottom line is that the spectral efficiency calculations should be done as consistently as possible.

From a network operator's perspective, what interests me is what spectrum efficiency can I get in a

certain amount of deployed spectrum (including guard bands).

The alternative approach would be do use only the carrier bandwidth without any guard bands. However,

in this case, for example, the UMTS bandwidth would be 3.84 MHz rather than 5 MHz.

David Shively

In principle, I agree with your underlying premise which I believe is that all proposals should state their overall

bandwidth requirements in a consistent way. However, I don't think your example is quite correct. For example,

I know that three cdma2000 carriers can be deployed in less than 2x5 MHz of spectrum (e.g. cdma450 deployments

which I believe are in about 2x4.5 MHz blocks) but W-CDMA cannot be deployed in less than 2x5 MHz and in fact,

I understand that it had to be modified to be deployable in the US PCS bands that are multiples of 2x5 MHz block sizes. So,

I don't believe that the 5 MHz W-CDMA channel bandwidth includes guardbands.

I believe it would be impossible to determine what would be the needed guardbands for protection of adjacent block licensees.

I think it would be make sense to include whatever spacing would be needed between multiple carriers in a single

If you agree, how about the following approach?:

"The network wide bandwidth is the total spectrum in use by the unique carriers deployed in the network, including any
required spacing between carriers."