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 : Choosing a discrete value that is near but not exactly at the analog signal level leads to a) PCM error b) Quantization error c) PAM error d) Sampling error
Last Answer : b) Quantization error
Description : Quantization noise can be reduced by ________ the number of levels. a) Decreasing b) Increasing c) Doubling d) Squaring
Last Answer : b) Increasing
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 : The length of the code-word obtained by encoding quantized sample is equal to a) l=log(to the base 2)L b) l=log(to the base 10)L c) l=2log(to the base 2)L d) l=log(to the base 2)L/2
Last Answer : a) l=log(to the base 2)L
Description : The first step in PCM is ________. A) quantization B) modulation C) sampling D) none of the above
Last Answer : sampling
Description : Mostly ________ is used in wireless LAN. a) time division multiplexing b) orthogonal frequency division multiplexing c) space division multiplexing d) channel division multiplexing
Last Answer : b) orthogonal frequency division multiplexing
Description : ________ is the method of encoding audio signals used in US standard 1544 kbit/s 24 channel PCM systems. A. Shannon’s law B. A-law C. Newton’s law D. Mu-law
Last Answer : D. Mu-law
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 : 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 : Cdma2000 1xEV was developed by ________ a) Motorola b) AT&T Laboratories c) Qualcomm d) NTT
Last Answer : c) Qualcomm
Description : In IPv4 layer, datagram is of ________ a) Fixed length b) Variable length c) Global length d) Zero length
Last Answer : b) Variable length
Description : Network layer at source is responsible for creating a packet from data coming from another ________ a) Station b) Link c) Node d) Protocol
Last Answer : d) Protocol
Description : In wireless network an extended service set is a set of ________ a) connected basic service sets b) all stations c) all access points d) connected access points
Last Answer : a) connected basic service sets
Description : PSTN is ___________ and wireless networks are ________ a) Highly dynamic, virtually static b) Static, virtually static c) Highly dynamic, virtually dynamic d) Virtually static, highly dynamic
Last Answer : d) Virtually static, highly dynamic
Description : PSTN stands for ________ a) Public switched telephone network b) Personal switched telephone network c) Personal switched telephone node d) Public switched telephone node
Last Answer : a) Public switched telephone network
Description : Which of the following scheme is used by Bluetooth? a) Frequency hopping TDD scheme b) Frequency hopping FDD scheme c) DSSS TDD scheme d) DSSS FDD scheme
Last Answer : a) Frequency hopping TDD scheme
Description : hich of the following burst is used to broadcast the frequency and time synchronization control messages? a) FCCH and SCH b) TCH and DCCH c) RACH and TCH d) FCCH and DCCH
Last Answer : a) FCCH and SCH
Description : An integrated circuit that performs the PCM encoding and decoding functions
Last Answer : Codec
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 : Which of the following has the function to accept information from PSTN? a) TIU b) WIU c) BIU d) CIU
Last Answer : a) TIU
Description : ___________ manages the switching function in GSM. a) BSS b) NSS c) OSS d) MSC
Last Answer : c) OSS
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 : 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 : In FM, frequency of modulated wave varies with A. amplitude B. time C. wavelength D. energy
Last Answer : time
Description : What is the reason why companding is employed in PCM systems? A. To overcome impulse noise in PCM receivers B. To allow amplitude limiting in the receivers C. To solve quantizing noise problem D. To protect small signals in PCM from quantizing distortion
Last Answer : D. To protect small signals in PCM from quantizing distortion
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 : 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
Description : 2G CDMA standard, IS-95, was proposed by which company? a) Nippon Telephone and Telegraph (NTT) b) Qualcomm c) Bellcore and Motorola d) AT&T Bell Laboratories
Last Answer : b) Qualcomm
Description : GSM (Global System for Mobile) was earlier also known as _____________ a) Group System Mobile b) Global Special Meaning c) Group Special Mobile d) Global Special Mobile
Last Answer : c) Group Special Mobile
Description : Which is one of the disadvantages of 2G standards? a) Short Messaging Service (SMS) b) Digital modulation c) Limited capacity d) Limited Internet Browsing
Last Answer : d) Limited Internet Browsing
Description : IS-136 uses which modulation technique? a) π/4 DQPSK b) BPSK c) GMSK d) AFSK
Last Answer : a) π/4 DQPSK
Description : IS-95 uses which modulation technique? a) GMSK b) BPSK c) QAM d) AFSK
Last Answer : b) BPSK
Description : Which modulation technique is used by GSM? a) GMSK b) BPSK c) QPSK d) GFSK
Last Answer : a) GMSK
Description : How many users are supported in IS-95 for each 1.25 MHz? a) Eight b) Sixty four c) Sixteen d) Twenty five
Last Answer : b) Sixty four