A certain telemetry signal with a duration of 20 seconds is known to have spectral components from near dc to about 1 kHz but has negligible spectral content above that frequency. The signal is to be recorded, converted in digital format, and stored in memory for subsequent processing. To ease in reconstruction of the signal, the sampling rate is to be selected 25% greater than the theoretical minimum. What is the minimum number of samples of the signal that must be taken?

A telephone subscriber line must have  above 40. What is the minimum number of bits per sample? 

Assume that a signal has been sampled and the sample amplitudes are between -20 and +20V. It was  decided to have eight levels (L = 8). What is the SQNR_dB?

Telephone companies digitize voice by assuming a maximum frequency of 4000 Hz. What should be the sampling rate?

A pulse modulation technique the process of which is equivalent to the process of converting analog signal to digital data.

A pulse modulation process that produces a 1-bit code which indicates an increase or decrease in the message signal’s amplitude.

The process of representing the sampled values of the amplitude by a finite set of levels.

In the receiver, a _________ filter is used to reconstruct (demodulate) PAM, PWM and PPM signals into a recovered message signal

Consider the analog signal 

x(t) = 3cos50πt  + 10sin300πt – cos100πt

The folding frequency is

Consider the analog signal 

x(t) = 3cos50πt  + 10sin300πt – cos100πt

The discrete time relative frequencies are

The theoretical minimum sampling rate

The amplitude of each pulse sample is proportional to the amplitude of the message signal at the time of sampling.

Sampling the message signal at regular intervals with a sample-hold (SH) circuit and producing pulse widths proportional to the message signal’s amplitude at the time of sampling.

Consider the analog signal 

x(t) = 3cos50πt  + 10sin300πt – cos100πt

Which component is sampled at its zero crossing points if the signal is sampled at 300 samples per second?

In a binary PCM system, the output signal-to-quantizing-noise ratio is to be held to a minimum of 40 dB. Determine the number of required levels.

A certain telemetry signal with a duration of 15 seconds is known to have spectral content from near dc to about 2 KHz but has negligible spectral content above that frequency. The signal is to be recorded, converted to digital format, and stored in memory for subsequent processing. Determine the theoretical minimum number of samples that must be taken if eventual reconstruction of the analog signal is desired.

A digital modulation scheme that conveys data by changing, or modulating, the amplitude and phase of a reference  carrier wave.

Which characteristic(s) of the carrier is being varied in Quadrature Phase Shift Keying (QPSK)

π /4 DQPSK system is used for the North American TDMA cell phone and PCS systems. This is actually a modified form of ______.

It involves the process of varying the frequency of a carrier wave by choosing one of two frequencies in correspondence to a sequence of digital pulses that constitute the information signal.

For a 64-PSK, the angular separation between any two adjacent phasors is _____________°

Gaussian minimum shift keying or GMSK is used in the GSM cellular radio and PCS systems. This is a modified form of ____

The digital modulation that is most bandwidth efficient is

Which characteristic(s) of the carrier is being varied in 64-QAM?

If the signal constellation has 2048 points, how many bits per baud can be sent?

Assuming d = 1, what is the required bandwidth for  16-QAM if you need to send 4 Kbps of data?

The bandwidth efficiency of a 64PSK is _______

A QPSK modulator has a bit rate fb of 20 Mbps. Its baud is_______

If ASK with 8 different amplitudes is used as a modulation technique, the number of bits/baud

If the signal constellation has 32 points, how many bits per baud can be sent?

For 4000 baud, 32-PSK modulation the bit rate is __________

For 3000 baud, FSK modulation the bit rate is ____

If the maximum message signal frequency is 4kHz and the sample pulse frequency is 12kHz, what frequencies are present in the second replica of the PAM signal?

Each bit in the code word of a binary PCM contributes ___dB to the output SQNR.

A foldover distortion that occurs when analog signals are sampled less than the theoretical minimum sampling rate.

Consider the analog signal 

x(t) = 3cos50πt  + 10sin300πt – cos100πt

The Nyquist rate for this signal is

Consider the analog signal 

x(t) = 3cos50πt  + 10sin300πt – cos100πt

The most appropriate sampling frequency for the signal x(t) is

On-off Keying (OOK) is an example of ______.

An 8-PSK  signal can undergo almost a ________° phase shift during transmission and still retain its integrity.

Assuming d = 1, what is the required bandwidth for  QPSK if you need to send 4 Kbps of data?

A BPSK modulator has a bit rate fb of 10Mbps. Its minimum Nyquist bandwidth is

A T-4 can multiplex how many voice channels?

The European standard E1 carrier system used in digital telephony has a transmission or data rate of?

In TDM, the transmission rate of the multiplexed path is usually _______ the sum of the transmission rates of the signal sources.

The process of simultaneously transmitting two or more signals over a single communication transmission medium.

For this type of multiplexing, the entire link bandwidth is available for each transmitting stations however, each station can only transmit at its assigned time slot.

In a multiplexed system, ____ lines share the bandwidth of _____ link.

A T2 line can multiplex how many voice band channels?

For this type of multiplexing, the available bandwidth is divided among transmitting stations with sufficient guard band in between them to avoid spectral overlapping. Since each station has its own sub-carrier frequency, simultaneous transmission among stations is possible. 

How many baseband voice channels does a jumbo group multiplex? 

The sharing of a medium and its link by two or more devices is called _____?

Multiplexing is a many-to-one process occurring at the transmitter. An equivalent one-to-many process occur at the receiver and this is referred to as _______

A supergroup has ____ of bandwidth and  multiplex ____ voice channels.

The European standard E1 carrier system can multiplex how many voice band channels?

A fixed time slots in a frame is referred to as

The word ______ refers to the portion of a _______ that carries a transmission.

A cable TV service uses a single coaxial cable with a bandwidth of 1.20 GHz to transmit multiple TV signals to subscribers. Each TV signal is 6 MHz wide. How many channels can be carried?

Assume that a voice channel occupies a bandwidth of 4 kHz. We need to multiplex 10 voice   channels with guard bands of 500 Hz using FDM. Calculate the required bandwidth. 

Consider a PAM – TDM system with 8 signals plus sync having a frame format of the form as illustrated below. Assume that each signal has a baseband characteristic and is band limited to W = 2 kHz. The sampling rate is to be 30% greater than the theoretical minimum Nyquist rate. (a) Using the 0.5/τ rule where  τ represents the pulse width, determine the approximate baseband bandwidth required for the composite PAM signal. (b) If the PAM signal is used to amplitude modulate a high-frequency RF carrier, determine the RF bandwidth required for the resulting high-frequency signal. NOTE: The 0.5/τ rule provides for the minimum bandwidth.

Consider a PAM – TDM system with 8 signals plus sync having a frame format of the form as illustrated below. Assume that each signal has a baseband characteristic and is band limited to W = 3 kHz. The sampling rate is to be 20% greater than the theoretical minimum Nyquist rate. (a) Using the 0.5/τ rule where  τ represents the pulse width, determine the approximate baseband bandwidth required for the composite PAM signal. 

Consider a PAM – TDM system with 8 signals plus sync having a frame format of the form as illustrated below. Assume that each signal has a baseband characteristic and is band limited to W = 2 kHz. The sampling rate is to be 30% greater than the theoretical minimum Nyquist rate. (a) Using the 0.5/τ rule where  τ represents the pulse width, determine the approximate baseband bandwidth required for the composite PAM signal. 

Consider a PAM – TDM system with 8 signals plus sync having a frame format of the form as illustrated below. Assume that each signal has a baseband characteristic and is band limited to W = 3 kHz. The sampling rate is to be 20% greater than the theoretical minimum Nyquist rate. If the PAM signal is used to frequency modulate a high-frequency RF carrier using 15 KHz deviation, determine the RF bandwidth required for the resulting high-frequency signal. NOTE: The 0.5/τ rule provides for the minimum bandwidth.

A PCM-TDM system multiplexes 24 voice-band channels. Each sample is encoded into seven bits, and a framing bit is added to each frame. The sampling rate is 9000 samples per second. Non - return - to zero (NRZ) encoding is the line format. Determine the maximum analog input frequency.

A PCM-TDM system multiplexes 20 voice-band channels. Each sample is encoded into eight bits, and a framing bit is added to each frame. The sampling rate is 10,000 samples per second. BPRZ-AMI encoding is the line format. Determine the  minimum Nyquist bandwidth.

A PCM-TDM system multiplexes 20 voice-band channels. Each sample is encoded into eight bits, and a framing bit is added to each frame. The sampling rate is 10,000 samples per second. BPRZ-AMI encoding is the line format. Determine the maximum analog input frequency.

A group of time slots is referred to as

WDM is a technique to combine:

Five data channels (digital), each transmitting at 1 Mbps, use a satellite link of 1.1 MHz.  Using Frequency Division Multiplexing with a guard band of 25 KHz  required between each channel to prevent interference, what modulation technique is appropriate for this system?

Five data channels(digital), each transmitting at 1.44 Mbps, use a satellite link of 1.3 MHz.  Using Frequency Division Multiplexing and a guard band of 25 KHz  required between each channel to prevent interference, what modulation technique is appropriate for this system?

A PCM-TDM system multiplexes 20 voice-band channels. Each sample is encoded into eight bits, and a framing bit is added to each frame. The sampling rate is 10,000 samples per second. BPRZ-AMI encoding is the line format. Determine the line speed (or transmission rate) in bps.

A PCM-TDM system multiplexes 24 voice-band channels. Each sample is encoded into seven bits, and a framing bit is added to each frame. The sampling rate is 9000 samples per second. Non - return - to zero (NRZ) encoding is the line format. Determine the minimum Nyquist bandwidth.

A PCM-TDM system multiplexes 24 voice-band channels. Each sample is encoded into seven bits, and a framing bit is added to each frame. The sampling rate is 9000 samples per second. Non - return - to zero (NRZ) encoding is the line format. Determine the line speed in bits per second.

A mastergroup has ____ of bandwidth and  multiplex ____ voice channels.

A jumbogroup has ____ of bandwidth and  multiplex ____ voice channels.

A group has ____ of bandwidth and  multiplex ____ voice channels.

Combines multiple streams into a single stream (many to one)

Separates the stream back into its component transmission (one to many) and directs them to their correct lines.

Refers to the physical path

Refers to the portion of a link that carries a transmission between a given pair of lines.

Channels can be separated by strips of unused bandwidth, to prevent signals from overlapping

The process of taking a group of bits from each input line for multiplexing

used when the data rate of the input links are multiples of each other.

used when there is a GCD between the data rates. The higher bit rate channels are allocated more slots per frame, and the output frame rate is a multiple of each input link.

used when there is no GCD between the links. The slowest speed link will be brought up to the speed of the other links by bit insertion, this is called pulse stuffing.

One application of ___ is the Synchronous Optical Network (SONET) in which multiple optical fiber lines are
multiplexed and demultiplexed.