Ec/Io usage

Dear User,

A more natural question would be: why we can not simply use the Signal Strength measured by the mobile as a guide for operations such as handover?

The answer is simple: the measured signal level corresponds to the Total RF power - All cells that the mobile sees.
So we need another quick and simple measure that allows us to evaluate the contribution of each sector individually.
We used to measure the pilot channel signal of each sector to assess the quality: if the level of the pilot is good, then also are good levels for the traffic channels for our call in this sector. Likewise, if the pilot channel is degraded, so will the other channels (including traffic) be, and it is best to avoid using the traffic channels in this sector.
UMTS and CDMA systems, we have a pilot channel, some other control channels such as paging, and traffic channels.
The Ec/Io varies with several factors, such as the Traffic Load and and RF Scenario.
Of course, the Ec/Io is the final composition of all these factors simultaneously (Composite Ec/Io), but it’s easier to understand talking about each one separately.

Regarding Eb/No, it is in the baseband after despreading and decoded only for one user - then we have a positive amount of energy over the total noise. It is measured at the output of receiver (NodeB, UE, etc).

Thanks!

Hello, dear!

Ec / Io and Eb / No are usually used in CDMA networks. They both mean signal-to-noise ratio. Ec / Io just accepts the signal drop at the receiving end without despreading and shrinking, so the useful signal is much smaller than the noise at this time. This value is all negative. 

Eb/No refers to the signal after despreading and combining, so the useful signal is stronger than the noise at this time (otherwise there will be a problem with calling), this value is usually positive.