Ec/Nt in atoll

[cesimkaol]

Ec/Nt - Eb/Nt parameters is confusing for me ,is anyone could you please explain that Ec/Nt and Eb/Nt?

Ec/Io is not equal Ec/Nt.Ec/Io is received signal power ratio to interference and we know that required value is equal or higher -13 dB.

But I could not understand that Ec/Nt and what is required value for optimization.and same question for Eb/Nt downlink and Eb/Nt uplink what is required value for these parametres.how can examine them in Atoll prediction.

Please Help.

These are confusing...:confused:

[no_1'sfasterthanradiowave]

Hi Dear,


EcIo is the received PCPICH code energy of the serving cell divided to spectral density of the noise (thermal, interference from other cells PCPICH, serving cell PCPICH and other channels power);

EcNt is the received PCPICH code energy of the serving cell divided to spectral density of thermal, interference from other cells PCPICH and other channels power;

It is quite realistic to have values for EcNt greater than zero while for EcIo you can measure maximum zero - own signal is included in denominator regardless of orthogonality!

Hope that helps :cool:!

[cesimkaol]

Thnx for ur interest but ı am aware of that what you explain.and ı am aware of that required EcIo . But ı dont know required values for UMTS for Eb/Nt and ı am confused about that Eb/Nt and Eb/No is same thing?

[faib]

hi dear ,

Ec/No , Ec/Io & Eb/No are all Signal to interference ratio , the only difference is "Signal" & "Interference Cloud" where practically Ec/No & Ec/Io are almost same figures (the difference is only one signal/user )

a) Ec/Io is Signal to interference ratio (SIR) measured at the input of the reciever( UE or NodeB) and it will be a negative value .

b) Eb/No is the signal to interference ratio (SIR) measured at the output of the reicever ( UE or NodeB) and it will be a positive value.

c) Eb/No is a positve SIR because of Gain of the system and in a digital system you need a minimum SIR working criteria for stable working and for each service (Voice /Data) you planned it accordingly (google it u ll get the details else check in ur respective vendor)

d)Difference in Ec/No and Ec/Io ------ Io is the total wide band power including Other cell interference and own cell interference where No exclude your own cell interference (for a user communicating with the system , its own cell signal is not an interference , so No figure just exclude that one ).

e)Now question is practically why we always measure or use Ec/Io because its difficult to to exclude ONE USER IMPACT in interference cloud .Thats the reason we can only have Ec/Io figures from Drive Test tools or scanner .


I hope you will now have a better idea about all these terms used in UMTS .

Keep spreading knowledge , finetopix rocks!

Regards,
Faib

[cesimkaol]

Faib thnx for your interest ...
Eb/No values are required for decode in decoder for per bit after despread signal in UE is that alright?
So there is required values for example 5dB for voice or 1,5 dB for 64 kbps data for separete bits from noise?