Software Defined Radio Multiple Choice Questions & Answers (MCQs) on “Software Component Characteristics”.
1. Which of the following is not present in the source segment of a mobile unit?
a) Narrowband ADCs
b) Source encoder
c) Source decoder
d) Interface to the PSTN
Answer: d
Clarification: Source segment of mobile unit differs from basestation. The mobile unit source segment comprises of source encoder, source decoder, narrowband ADCs, and narrowband DACs. The bases tation consists of interface to the public switched telephone network for access to remote source coding.
2. ____ is the process of non-linear compression and expansion of analog electronic signal.
a) Quantization
b) Companding
c) Pulse code modulation
d) Modulation
Answer: b
Clarification: Companding is the process of non-linear compression and expansion of analog electronic signal. The dynamic range of the signal is compressed at the transmitter and is expanded to the normal range at the receiver. It helps in the preservation of information content.
3. CELP stands for ____
a) Codebook Evolved Linear Processing
b) Codebook Excited Linear Prediction
c) Cross-correlation Excited Linear Prediction
d) Cross-correlation Evolved Linear Processing
Answer: b
Clarification: Codebook Excited Linear Prediction is a linear speech coding algorithm. It uses an adaptive and a fixed codebook as the input of the linear prediction model.
4. ____ software supports system control and user-interface functions.
a) Voice processing
b) Mode processing
c) Message processing
d) Network processing
Answer: c
Clarification: Message processing software supports system control and user-interface functions. It sets up the direction of the channel, its associated crypto algorithm, AGC loop bandwidth, and transmission and reception parameters.
5. User interface software allows the ____ of ____ between a core system processor and an external head.
a) direction, signal
b) distribution, channel control
c) distribution, signal
d) direction, channel control
Answer: b
Clarification: User interface software determines and controls status externally. User interface software allows the distribution of channel control between a core system processor and an external head. The core system processor implements user interface functions. The external head may request status and provide control parameters.
6. The ____ function is used to connect two front end channels.
a) joining
b) assembling
c) bridging
d) cooperative
Answer: c
Clarification: The front end channels typically operate in different modes and bands. The bridging function is used to connect two front end channels. For example a standard radio can be bridged with frequency hopped radio using bridging function.
7. ____ messages hold setup information for digitally vocoded voice.
a) Bitstream
b) INFOSEC
c) Modem
d) Internetworking
Answer: d
Clarification: Internetworking messages hold setup information for digitally vocoded voice, along with the type of vocoder, and the associated data rate. Internetworking also uses ACK, NACK, buffer management, and message forwarding functions.
8. Which of the following is not an SDR function associated with presentation layer?
a) Radio network configuration
b) Encryption
c) Virtual terminals
d) Object request broker
Answer: a
Clarification: Encryption, virtual terminals, object request broker for interconnecting applications are the SDR functions associated with presentation layer. The presentation layer provides translation and mappings with control code translations.
9. Which of the following is not a responsibility of the data link layer?
a) Framing
b) Integration
c) Addressing
d) Error control
Answer: b
Clarification: The data link layer is responsible for framing, physical addressing and error control. It also retransmits packet if necessary. The SDR functions include creation of point to point interface and adaptive quality management.
10. Bitstream processing performs _____
a) data encryption
b) transmission termination
c) connection tests
d) frame alignment
Answer: d
Clarification: Data encryption, transmission termination, and frame alignment are functions carried out by INFOSEC processing software. Frame alignment, bit stuffing and bit interleaving are functions of bitstream processing software.