Description : The signals which are obtained by encoding each quantized signal into a digital word is called as a) PAM signal b) PCM signal c) FM signal d) Sampling and quantization
Last Answer : b) PCM signal
Description : In PCM encoding, quantization level varies as a function of ________ a) Frequency b) Amplitude c) Square of frequency d) Square of amplitude
Last Answer : b) Amplitude
Description : The process of dividing an analog signal into a string of discrete outputs, each of constant amplitude, is called: (A) Strobing (B) Amplification (C) Conditioning (D) Quantization
Last Answer : (D) Quantization
Description : The most common technique to change an analog signal to digitaldata is called __________. A) PAL B) PCM C) sampling D) none of the abov
Last Answer : PCM
Description : The first step in PCM is ________. A) quantization B) modulation C) sampling D) none of the above
Last Answer : sampling
Description : In a PCM system the number of quantization level are 16 and the maximum signal frequency is 4 KHz the transmission bit rate is
Last Answer : In a PCM system the number of quantization level are 16 and the maximum signal frequency is 4 KHz the transmission bit rate is 32 Kbits/sec
Description : Quantization noise can be reduced by ________ the number of levels. a) Decreasing b) Increasing c) Doubling d) Squaring
Last Answer : b) Increasing
Description : Which causes a quantization noise in PCM system? A. Serial transmission errors B. The approximation of the quantized signal C. The synchronization between encoder and decoder D. Binary coding techniques
Last Answer : B. The approximation of the quantized signal
Last Answer : The approximation of the quantized signal
Description : What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB
Last Answer : B. 50 dB
Description : Steps to follow to produce PCM signal. A. Quantizing, sampling, and coding B. Sampling, quantizing, and coding C. Sampling, coding and quantizing D. Coding, quantizing and coding
Last Answer : B. Sampling, quantizing, and coding
Description : Which of the following leads to the 3G evolution of GSM, IS-136 and PDC systems? a) W-CDMA b) GPRS c) EDGE d) HSCSD
Last Answer : a) W-CDMA
Description : Which of the following leads to evolution of 3G networks in CDMA systems? a) IS-95 b) IS-95B c) CdmaOne d) Cdma2000
Last Answer : d) Cdma2000
Description : Quantizing noise occurs in A. PCM B. PLM C. PDM D. PAM
Last Answer : A. PCM
Description : In PCM, it converts the PAM sampled to parallel PCM codes
Last Answer : Analog-to-Digital converter
Description : What is the raw channel bit error rate of Bluetooth? a) 10-3 b) 10-10 c) 103 d) 10-1
Last Answer : a) 10-3
Description : In PCM system, if we increase the quantization levels from 2 to 8, the relative bandwidth requirements will: (1) Be doubled (2) Remain same (3) Be tripled (4) Becomes eight times
Last Answer : In PCM system, if we increase the quantization levels from 2 to 8, the relative bandwidth requirements will: Be tripled.
Description : In a PCM system of telemetry, the quantization noise depends on: (1) The sampling rate and quantization level (2) The sampling rate only (3) The number of quantization level (4) Information provided is not sufficient
Last Answer : In a PCM system of telemetry, the quantization noise depends on: The number of quantization level.
Description : The analog signal needs to be sampled at a minimum sampling rate of: (A) 2fs (B) 1/(2fs) (C) fs/2 (D) 2/fs
Last Answer : (A) 2fs
Description : The analog signal m(t) is given below m(t) = 4 cos 100 pt + 8 sin 200 pt + cos 300 pt, the Nyquist sampling rate will be: (1) 1/100 (2) 1/200 (3) 1/300 (4) 1/600
Last Answer : The analog signal m(t) is given below m(t) = 4 cos 100 pt + 8 sin 200 pt + cos 300 pt, the Nyquist sampling rate will be: 1/300
Description : What is the advantage of PTM over PAM? A. All of these B. Low sampling rate is required C. Much better noise immunity D. Simpler to generate
Last Answer : C. Much better noise immunity
Description : The process of representing Infinite set of values with a much smaller set is called a. Mapping b. clustering c. Quantization d. Sampling
Last Answer : c. Quantization
Description : Information per source is called a. A. sampling b. B. quantization c. C. entropy d. D. normalization
Last Answer : c. C. entropy
Description : Which type of cell provides the best level of service for average subscribers? a) Acceptance cell b) Barred cell c) Reserved cell d) Suitable cell
Last Answer : d) Suitable cell
Description : Which of the following is the world’s first cellular system to specify digital modulation and network level architecture? a) GSM b) AMPS c) CDMA d) IS-54
Last Answer : a) GSM
Description : 12 voice channels are sampled at 8000 sampling rate and encoded into 8 bit PCM word. Determine the rate of the data stream. a. 354 kbps b. 750 kbps c. 768 kbps d. 640 kbps
Last Answer : c. 768 kbps
Description : ECE Board Exam March 1996 According to the Nyquist theorem, the sampling rate that can be used in a PCM system is ________ the highest audio frequency. A. once B. eight times C. twice D. thrice
Last Answer : C. twice
Description : A theory that establishes the minimum sampling rate that can be used for a given PCM systems.
Last Answer : Nyquist sampling theorem
Description : A theory that establishes the minimum sampling rate that can be used for a given PCM systems
Description : The most common method used for sampling voice signals in PCM systems.
Last Answer : flat top sampling
Description : _______ is more prevalent in analog signals that have steep slopes or whose amplitudes vary rapidly. A. Peak limiting B. Quantization noise C. Granular noise D. Slope overload
Last Answer : D. Slope overload
Description : Which of the following steps is/are not required for analog to digital conversion ? (a) Sensing (b) Conversion (c) Amplification (d) Conditioning (e) Quantization Codes : (A) (a) and (b) (B) (c) and (d) (C) (a), (b) and (e) (D) None of the above
Last Answer : (D) None of the above
Description : The use of non-uniform quantization leads to: (1) Reduction in transmission bandwidth. (2) Increase in maximum SNR. (3) Increase in SNR for signal levels. (4) Simplification of quantization process.
Last Answer : The use of non-uniform quantization leads to: Increase in SNR for signal levels.
Description : ECE Board Exam March 1996 Which of the following pulse modulation systems is analog? A. Delta B. Differential PCM C. PWM D. PCM
Last Answer : C. PWM
Description : PCM is an example of _______ conversion. A) digital-to-digital B) digital-to-analog C) analog-to-analog D) analog-to-digital
Last Answer : analog-to-digital
Description : Which performance parameter is the minimum amount of optical power required to achieve a specific bit-error rate (BER) in digital systems or a given signal-to-noise ratio (SNR) in analog systems?
Last Answer : Receiver sensitivity.
Description : _______ data have discretestates and take discrete values. A) Analog B) Digital C) (a) or (b) D) None of the above
Last Answer : Digital
Description : Which of the following is not backward compatible with Cdma2000? a) Cdma2000 1xRTT b) Cdma2000 3xRTT c) Cdma2000 1xEV-DO d) Cdma2000 1xEV-DT
Last Answer : c) Cdma2000 1xEV-DO
Description : What are the two options provided by Cdma2000 1xEV? a) Cdma2000 1xRTT. Cdma2000 3xRTT b) Cdma2000 1xEV-DO, Cdma2000 1xEV-DV c) Cdma2000 1xEV-DT, Cdma2000 1xEV-DO d) Cdma2000 1xRTT, Cdma2000 1xEV-DV
Last Answer : b) Cdma2000 1xEV-DO, Cdma2000 1xEV-DV
Description : How is bandwidth increased in Cdma2000? a) Clubbing adjacent radio channels b) Changing the hardware of base stations c) Change of spectrum d) Change of RF equipment
Last Answer : a) Clubbing adjacent radio channels
Description : Cdma2000 1xEV was developed by ________ a) Motorola b) AT&T Laboratories c) Qualcomm d) NTT
Last Answer : c) Qualcomm
Description : Which of the following is not a characteristic of Cdma2000? a) Adaptable baseband signalling rates b) Adaptable baseband chipping rates c) Multicarrier technologies d) OFDMA
Last Answer : d) OFDMA
Description : Cdma2000 works in TDD mode only. a) True b) False
Last Answer : b) False
Description : How many users are supported by Cdma2000 1X in comparison to 2G CDMA standard? a) Half b) Twice c) Six times d) Ten times
Last Answer : b) Twice
Description : Within ITU IMT-2000 body, Cdma2000 1xRTT is also known as ____________ a) Cdma2000 1xEV-DO b) Cdma2000 1xEV-DV c) IS-95B d) G3G-MC-CDMA-1X
Last Answer : d) G3G-MC-CDMA-1X
Description : Which of the following the first 3G CDMA air interface? a) IS-95 b) IS-95B c) Cdma2000 1xRTT d) CdmaOne
Last Answer : c) Cdma2000 1xRTT
Description : 2G and 2.5G CDMA operators may selectively introduce 3G capabilities at each cell without changing entire base stations and reallocate spectrums. a) True b) False
Last Answer : a) True
Description : Which of the following has no backward compatibility with 3G Cdma2000? a) IS-95 b) GPRS c) IS-95A d) IS-95B
Last Answer : b) GPRS
Description : The 2G GSM technology uses a carrier separation of _____________ a) 1.25 MHz b) 200 KHz c) 30 KHz d) 300 KHz
Last Answer : b) 200 KHz
Description : Which one of the following 2G standard is used in Japan? a) IS-136 b) GSM c) PDC d) AMPS
Last Answer : c) PDC