LTE800/CDMA850 Interference issue

[hamody2005]

dear all expert I need help from everyone who can help about the LTE800/CDMA850 Interference issue. -what is the effect of LTE800 on CDMA850 and CDMA850 on LTE800. -which on is more harmful on others. - what is the precaution that must be taken before deploying LTE800. i will appreciate your help

[Optimustron]

I don't know exactly the effect, but in my experience between UMTS and GSM in the same band I recommend you that put the more sensitive technology at lower band, why because if you have problems with intermodulation, IMD, and armonics then you reduce the problem, when you have high order modulation like LTE does it is more sensitive to interference and lower distance to have good quality then you need to check the spectrum before the deployment and be sure to have clean the band that you are going to use, CDMA is a narrow band technology, 1.24 Mhz compared to LTE at least 10 Mhz, then if you see the power of both in a Spectrum Analyzer, you will see that for the same setting, we are going to say 20 watts/43 dBm, you will see a bigger signal for CDMA than LTE, this is because you need to remember that the power is the area under the curve. Why I said that because then the IMD, intermodulation will be stronger for a particular bandwidth and armonics too, then is better to put LTE at lower band.

You need check too ACP, ADJACENT CHANNEL POWER, or ACLR, ADJACENT CHANNEL LEAKAGE POWER in order to reduce the possibilities of interference mainly if you don't have guard band that all the time is the case. You can reduce futher the possibilities if you have an adecuate isolation between antennas, if you get more than 30 dB of isolation that is better.

I hope this can help you, best regards friend,