[SOLVED] Confirm "spurious emissions spec of <-36 dBm/100 kHz"?

[tony_lth]

I read this sentence:
LTE has a spurious emissions spec of <-36 dBm/100 kHz in the frequency range of 30 MHz to 1 GHz (refer to Section 6.6.3 in the 3GPP TS 36.101 V 9.5.0).

I want to confirm it's meaning is: Per 100KHz, the spurious emissions power is less than -36dBm, right?
How to measure it? If use spectrum analysis, set RBW=100KHz, so the noise floor should be less than -36dBm, right?

I appreciate your reply. Thanks.

 

[FvM]

I guess, a RBW of 100 kHz will be hardly able to check the specification. You'll rather determine the output spectrum with considerable higher resolution. I'm not engaged with LTE, but I'm sure there will be a test specification prescribing a measurement method for the spectrum mask.

 

[tony_lth]

Now it is easy for test, connect all the instruments and DUT, then run the program, every specification can be tested AUTO.
But there are many facts masked under the AUTO system.

 

[vfone]

LTE has a spurious emissions spec of <-36 dBm/100 kHz in the frequency range of 30 MHz to 1 GHz (refer to Section 6.6.3 in the 3GPP TS 36.101 V 9.5.0).
I want to confirm it's meaning is: Per 100KHz, the spurious emissions power is less than -36dBm, right?
How to measure it? If use spectrum analysis, set RBW=100KHz, so the noise floor should be less than -36dBm, right?

The 3GPP spurious emissions for all cellular systems as GSM, WCDMA, LTE, has almost the same requirements.
You are right, have to set the RBW of the SA to 100kHz in the automated system. As a general rule, the noise floor of the spectrum analyzer should be at least 10dB lower than the measurement level, but this is an easy to meet requirement for the latest SA. Every spurious higher than -36dBm will be a failure.

 

[MK28]

@tony: as vofone mentioned the requirements are same..now you can verify it on your own if you want to know your DUT performance.

Setup:
DUT>CPL>ATTN.>NOTCH FILTER> SA (if it's a gated measurement then SA need trigger)

CPL path could go to CMU200/CMW (i assume you want to measure it at max TX out)

Measurement:

There are several steps to walk through and it starts I assume, some kHz upto GHz and usually these are done in several steps i.e:
Step 1: x kHz to y MHz
Step 2: x1 MHz to y1MHz
.....
.....
.....

For every steps your RBW may vary and higher the RBW more noise will be integrated in your measurements ..in any case, it is wise to note down the SA noise floor before you kick off the work. Of course it depends on what is output power level (whether it is output of TRX or ANT) you are transmitting at. Depending your TX output, and assuming mesurement setups are understood then you should be able to see @ channel/freq. of interest @offset spurious level.