CDMA Near-Far Problem
A mobile station that is close to a base station and another mobile station that is far from the base station both attempt to interact with the base station at the same time, which is known as the near-far problem in CDMA. The signal from the mobile station that is near the base station may be significantly stronger than the signal from the mobile station that is far away, which can lead to the loss or significant degradation of the signal from the far mobile station. Reduced network bandwidth and coverage may follow from this.
for example, let’s consider three stations A, B, and C, here terminals A and B send and C receives. The signal strength decreases proportional to the square of the distance, the signal of B, therefore, drowns out A’s Signal, as a result, C cannot able to receive A.
Due to the fact that handsets may be located anywhere within a given cell’s boundaries, the CDMA near-far issue exists. While some handsets will be relatively near to the base station, others will be far away.
In a free space situation or according to the inverse square rule, the signal strength drops by a factor of two with increasing distance.
Signal = k/(d^2)
Where: k = a constant
d = distance
CDMA Near Far Problem
Multiple users can share the same frequency band with CDMA (Code Division Multiple Access) wireless communication technology because it uses distinct codes to distinguish each user’s signals. However, CDMA can experience the near-far issue, just like other wireless transmission technologies.