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Computer Networks → Introduction to Computer Networks 40

What is STBC (Space-Time Block Coding)
Transmit diversity encoding across antennas and time slots
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What is BLAST in MIMO
Bell Labs Layered Space-Time architecture for spatial multiplexing
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What is zero-forcing equalizer in MIMO
Canceling inter-stream interference using matrix inversion
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What is MMSE equalizer in MIMO
Minimum Mean Square Error equalizer balancing noise and interference
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What is successive interference cancellation (SIC)
Decoding streams one by one subtracting each decoded stream
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What is link budget
Calculating signal strength accounting for all gains and losses
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What is path loss exponent
Rate at which signal attenuates with distance
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What is shadowing in wireless
Signal variation due to obstacles like buildings and terrain
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What is Rayleigh fading
Fading from multipath without dominant LOS component
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What is Rician fading
Fading with dominant LOS component plus multipath
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What is coherence bandwidth in wireless
Frequency range over which channel response is correlated
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What is coherence time in wireless
Time duration over which channel is approximately constant
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What is Doppler effect in wireless
Frequency shift due to relative motion between transmitter and receiver
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What is guard interval in OFDM purpose
Preventing inter-symbol interference from multipath delay spread
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What is subcarrier spacing in 5G NR FR1
15 30 or 60 kHz depending on numerology
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What is 5G numerology
Subcarrier spacing configuration (mu=0 to 4)
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What is 5G slot duration for 30 kHz SCS
0.5 ms (1 ms for 15 kHz mu=0)
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What is mini-slot in 5G NR
2 4 or 7 symbol transmission for low latency
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What is BWP (Bandwidth Part) in 5G NR
Configurable portion of cell bandwidth for UE operation
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What is beam management in 5G NR
Selecting and maintaining optimal beam between gNB and UE
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What is beam sweeping in 5G NR
Transmitting reference signals across different beam directions
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What is beam failure recovery
UE detecting beam failure and requesting new beam
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What is CSI-RS in 5G NR
Channel State Information Reference Signal for channel estimation
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What is SSB (Synchronization Signal Block) in 5G NR
PSS SSS and PBCH for initial cell access
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What is 5G NR PRACH
Physical Random Access Channel for initial network access
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What is MAC-CE in 5G NR
MAC Control Element for in-band signaling
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What is PDSCH scheduling in 5G NR
DCI in PDCCH allocates resources for PDSCH data
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What is PUSCH scheduling in 5G NR
DCI or configured grant allocates PUSCH resources
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What is DCI (Downlink Control Information)
Control signaling in PDCCH scheduling UL/DL resources
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What is UCI (Uplink Control Information)
Control signaling in PUSCH/PUCCH carrying CQI HARQ SR
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What is 5G NR CQI purpose
UE reports channel quality for adaptive modulation coding
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What is PMI (Precoding Matrix Indicator)
UE recommendation for beamforming precoding matrix
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What is RI (Rank Indicator) in 5G
Number of spatial layers UE can receive
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What is TDD vs FDD in LTE/5G
TDD shares frequency using time slots FDD uses separate UL DL frequencies
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What is dynamic TDD in 5G NR
Flexible UL/DL slot configuration changed per slot
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What is network slicing NSMF
Network Slice Management Function managing slice lifecycle
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What is NEST in network slicing
Network Slice Type describing slice characteristics
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What is slice isolation requirement
Performance guaranteed for slice even with other slices present
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What is E2E network slice
Slice spanning RAN core and transport domains
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What is slice SLA assurance
Monitoring and ensuring slice meets committed performance
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