Problem 1:
a.) What is the minimum Eb/Ieff (bit energy over effective noise energy) to yield P(e)<1% in the asynchronous CDMA system (additive white Gaussian noise, no multipath)?
b.) If the spectral efficiency is 1chip/sec/Hz, bandwidth is 3MHz, chip energy Ec=0.1No, data rate per user=10kbit/sec/user, and P(e)<1%, how many users can be supported in a single cell?
the desired signal energy is N*N*Ec
the energy for one interferer is N*Ec
the noise energy is N*No)
Problem 2:
The minimum Eb/Ieff (bit energy over noise energy) per user in the uplink of an asynchronous CDMA system is 2. The spectral efficiency is 1chip/sec/Hz. The bandwidth of the available spectrum is 2MHz. Data rate per user 10kbit/sec/user. The received chip energy at the base station for a user is Ec=No(10^9)/(r^3) where r is the distance (in meters) between the user and the base station.
(Note that No is noise power spectral density (unit is Energy per sec per Hz) and therefore its unit is energy. )
Consider the case that all users have the same distances from the base station.
1) What is the maximum range of coverage, if the number of user Nu=100?
2) What is maximum number of users Nu and the corresponding processing gain N for r=100m?
3) What is maximum number of users Nu and the corresponding processing gain N for r=1km?
4) What is maximum number of users Nu and the corresponding processing gain N for r=3km?
5) What is maximum number of users Nu and the corresponding processing gain N for r=5km?
Attachment:- assignment56033.pdf