{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# HW10 - Chapter7PartIII MULTIPLEACCESS Deptof

This preview shows pages 1–2. Sign up to view the full content.

Homework 10 Problem 1 Consider a system with 3 CDMA users. a. Use a coin to generate a random sequence of length 32 for each of the 3 users. b. Find the correlation of the sequence of the first user with itself (answer: 32) and with each of the other two users (call that 1 N and 2 N ). Also, find the value of 2 1 N N + . c. If the first user sent 1, he would receive a value 2 1 N N N Y + + = ? If instead he sent -1, he would have received instead 2 1 N N N Y + + - = . Suppose in the above experiment, he sent 1. What would be a reasonable way to decide if 1 or -1 was sent? In your experiment, would he have made an error in deciding? d. In general, we may have K users and each user uses a random sequence of length N as its CDMA code. It can be shown that the correlations of the first sequence with any one of the K-1 other sequences is a sum of N Bernoulli random variables (values = 1 or -1 with equal probability of ½). Therefore the correlation of the first sequence with any other sequence has mean zero and variance N . In order words, after de-spreading,

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 3

HW10 - Chapter7PartIII MULTIPLEACCESS Deptof

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online