outage probability

[logistic_guy]

In this problem we will explore the impact of different log-normal shadowing parameters on outage probability. Consider a cellular system where the received signal power is distributed according to a log-normal distribution with mean $\displaystyle \mu_{\psi} \ \text{dBm}$ and standard deviation $\displaystyle \sigma_{\psi} \ \text{dBm}$. Assume the received signal power must be above $\displaystyle 10 \ \text{dBm}$ for acceptable performance.

(a) What is the outage probability when the log-normal distribution has $\displaystyle \mu_{\psi} = 15 \ \text{dBm}$ and $\displaystyle \sigma_{\psi} = 8 \ \text{dBm}$?
(b) For $\displaystyle \sigma_{\psi} = 4 \ \text{dBm}$, find the value of $\displaystyle \mu_{\psi}$ required for the outage probability to be less than $\displaystyle 1\%$ – a typical value for cellular systems.
(c) Repeat part (b) for $\displaystyle \sigma_{\psi} = 12 \ \text{dBm}$.
(d) One proposed technique for reducing outage probability is to use macrodiversity, where a mobile unit’s signal is received by multiple base stations and then combined. This can only be done if multiple base stations are able to receive a given mobile’s signal, which is typically the case for $\displaystyle \text{CDMA}$ systems. Explain why this might reduce outage probability.

 

[khansaheb]

In this problem we will explore the impact of different log-normal shadowing parameters on outage probability. Consider a cellular system where the received signal power is distributed according to a log-normal distribution with mean $\displaystyle \mu_{\psi} \ \text{dBm}$ and standard deviation $\displaystyle \sigma_{\psi} \ \text{dBm}$. Assume the received signal power must be above $\displaystyle 10 \ \text{dBm}$ for acceptable performance.

(a) What is the outage probability when the log-normal distribution has $\displaystyle \mu_{\psi} = 15 \ \text{dBm}$ and $\displaystyle \sigma_{\psi} = 8 \ \text{dBm}$?
(b) For $\displaystyle \sigma_{\psi} = 4 \ \text{dBm}$, find the value of $\displaystyle \mu_{\psi}$ required for the outage probability to be less than $\displaystyle 1\%$ – a typical value for cellular systems.
(c) Repeat part (b) for $\displaystyle \sigma_{\psi} = 12 \ \text{dBm}$.
(d) One proposed technique for reducing outage probability is to use macrodiversity, where a mobile unit’s signal is received by multiple base stations and then combined. This can only be done if multiple base stations are able to receive a given mobile’s signal, which is typically the case for $\displaystyle \text{CDMA}$ systems. Explain why this might reduce outage probability.

show us your effort/s to solve this problem.