Question

The American Standard Code for Information Interchange (ASCII) has 128 binary-coded characters. A certain computer generates data at 1,000,000 characters per second. For single error detection, an additional bit (parity bit) is added to the code of each character. What is the minimum bandwidth required to transmit this signal.

Answer 1

The minimum bandwidth required to transmit ASCII characters with single error detection at 1,000,000 characters per second, assuming a parity bit is added to each character, is 8 Mbps. This figure is based on 8-bit as characters and could vary depending on the modulation technique used.

Step-by-step explanation:

The minimum bandwidth required to transmit a signal with single error detection for ASCII characters at a rate of 1,000,000 characters per second can be calculated considering the addition of a parity bit to each character. ASCII uses 7 bits per character, making it 8 bits with the parity bit. To find the bandwidth, we multiply the bit rate per character by the number of characters per second. Since the computer generates data at 1,000,000 characters per second, and with the parity bit, we have an 8-bit as character, the data rate becomes 8,000,000 bits per second (or 8 Mbps).

However, the bandwidth can also be affected by various factors such as the modulation technique used. For instance, if a simple binary modulation scheme is used (such as non-return-to-zero, NRZ), where one bit is transmitted per signal change, the bandwidth would be 8 Mbps. But if a more complex modulation scheme is used, which transmits more than one bit per signal change, the required bandwidth could be lower.

Answer 2

The minimum bandwidth required to transmit a signal generated at a rate of 1,000,000 ASCII characters per second, with an added parity bit for single error detection, is 4 MHz. This calculation is based on the bit rate of 8 million bits per second and assumes a binary signal requiring a minimum bandwidth that is half of the bit rate.

Step-by-step explanation:

The question pertains to digital data transmission and requires calculating the minimum bandwidth necessary for a computer that generates data at a rate of 1,000,000 characters per second, using ASCII which has 7-bit binary-coded characters and includes an additional parity bit for error detection, making it 8 bits per character in total.

Bandwidth, in this context, refers to the range of frequencies necessary to transmit the digital signal. The data rate of the signal is given as 1,000,000 characters per second, and since each character is represented by 8 bits (7 bits for ASCII character and 1 for parity), the bit rate is 8,000,000 bits per second, or 8 Mbps (Megabits per second).

To calculate the minimum bandwidth using the Nyquist formula, we assume the signal is binary and requires a minimum bandwidth that is half of the bit rate. Hence, the minimum bandwidth required is 4 MHz (megahertz). This is because the maximum rate of change of a binary signal would be if it alternated between 0 and 1 for every bit, so the minimum bandwidth is also known as the Nyquist bandwidth.