/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 103 A transmitter is sending a messa... [FREE SOLUTION] | 91Ó°ÊÓ

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A transmitter is sending a message using a binary code, namely, a sequence of 0 's and 1 's. Each transmitted bit \((0\) or 1\()\) must pass through three relays to reach the receiver. At each relay, the probability is \(.20\) that the bit sent on is different from the bit received (a reversal). Assume that the relays operate independently of one another: transmitter \(\rightarrow\) relay \(1 \rightarrow\) relay \(2 \rightarrow\) relay \(3 \rightarrow\) receiver a. If a 1 is sent from the transmitter, what is the probability that a 1 is sent on by all three relays? b. If a 1 is sent from the transmitter, what is the probability that a 1 is received by the receiver? (Hint: The eight experimental outcomes can be displayed on a tree diagram with three generations of branches, one generation for each relay.)

Short Answer

Expert verified
a. The probability that a 1 is sent on by all three relays is 51.2%. b. The probability that a 1 is received by the receiver is 60.8%.

Step by step solution

01

Understanding Relays Acting Independently

Given that the probability that a bit is reversed is .20 for each relay and these relay events happen independently, the probability that a particular event does not happen is 1 - Probability(event happens). In this case, the probability that the bit sent is not reversed, or maintains the same value at each relay is 1 - .20, which equals .80 or 80%.
02

Probability of All Relays Not Reversing

To find the probability of a sequence of independent events all happening, we multiply the probabilities of each event. Here, we want the bit to maintain its value (a 1) at each of the three relays. Thus, we multiply the probability of maintaining value at each relay, which is (.80)*(.80)*(.80) = .512 or 51.2%.
03

Calculate the Probability of Receiver Received 1

This calculation involves every possible outcome where the receiver receives 1. The 1s can be received by directly transmitting the 1 without being reversed, or it can be reversed twice (0->1->0->1 or 1->0->1->0). To calculate the probability that a 1 is received by the receiver, we need to add up the probabilities for each possible outcome where a 1 is received: unchanged at any relay, and reversed twice. The probability of reversing twice is: .20 * .20 * .80 (reversed at relays 1 and 2, but not at 3) + .20 * .80 * .20 (reversed at relays 1 and 3, but not at 2) + .80 * .20 * .20 (reversed at relays 2 and 3, but not at 1) = 3*(.20^2)*.80 = .096. Now, combine the two probabilities to get the final answer: .512 + .096 = .608 or 60.8%.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Independent Events
In probability theory, independent events are those whose outcomes do not affect each other. This is an important concept when analyzing relay systems in communication. Each relay operates independently, meaning that whether a bit is reversed or not at one relay does not influence the outcome at another. This lack of influence can make calculations simpler and will allow us to compute the probability of sequences of events using multiplication.

For the problem at hand, the relays in the binary code transmission system are independent. This means the likelihood of the bit either staying the same or being reversed at one relay doesn’t affect the next relay. If Relay 1 sends a bit with a reversal probability of 0.20, Relay 2 also has a 0.20 reversal probability, independent of Relay 1’s outcome.

This independence makes it possible to calculate complex probabilities for scenarios involving multiple events by multiplying the probability of each event occurring. This system simplifies our task of determining specific outcomes in the coding process.
Binary Code Transmission
Binary code transmission involves sending information through sequences of 0s and 1s, where each bit can be independently transmitted across a network. In the exercise example, a binary sequence is sent through several relays, increasing chances for errors. Understanding how this system works is crucial for calculating transmission success.

When 1 is the bit sent from the transmitter, the system encompasses potential errors known as reversals, where the probability for each relay flipping the bit is 0.20. This risk impacts the overall transmission integrity. The main struggle in binary code transmission is combating these potential errors by employing mechanisms to reduce error rates, such as multiple transmissions or error-checking protocols.

In practical communication systems, handling errors and ensuring high-quality transmission reliability is vital, impacting data fidelity and necessary error correction methods to maintain transmission accuracy.
Tree Diagram Analysis
Tree diagrams are helpful visualization tools that display possible outcomes in probability problems. For the binary code transmission exercise, a tree diagram helps illustrate all potential scenarios of the bit (0 or 1) traveling through the three independent relays. Each level of the tree represents a relay, with branches showing outcomes: unchanged or reversed.

These diagrams elucidate the probability paths creating each outcome, assisting in identifying successful transmission scenarios. For instance, following a straight line through unchanged branches visualizes the path where the transmitted bit remains "1" through all relays. Alternative paths highlight where the bit might change states due to reversals, giving a detailed view of possible outcomes and their likelihood.

Constructing a tree diagram organizes complex probabilities into simple visual terms, helping visualize and solve problems in a systematic way by analyzing each potential outcome together.
Relay Systems in Communication
Relay systems are instrumental in transmitting information over distances, especially where direct transmission is challenging. In this exercise, the system's relay components retransmit or "boost" signals, passing data from one point to another.

Each relay has a chance to introduce errors, shown by the 0.20 probability of a bit reversal. However, the system's design assumes independence, reducing complication as errors at one relay don’t impact the next. Understanding relay system functionality assists in calculating transmission accuracy and in engineering systems for reliable communication.

Effective communication systems minimize error rates, employing relay structures strategically to boost signal strength and ensure accurate delivery. This process underlines the importance of engineering solutions that mitigate risk and enhance the correctness of transmitted data, thus maintaining system reliability and efficiency.

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Most popular questions from this chapter

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