Digital Modulation Overview
- Introduction to key wireless standards
- IS-95, GSM
- Multiple access principles (TDMA, CDMA, FDMA, SDMA)
- Complex envelope representation of signals and systems
- Bridge relationship to actual hardware
- Provide mathematical insight
- Support computer simulation
- Stochastic theory review
- Digital modulation theory
- BPSK, QPSK, OQPSK, MSK, GMSK, 16QAM, 64QAM, etc.
- Pulse shaping filter selection (Nyquist and Raised Cosine filtering)
- Nonlinear amplification (spectral regrowth)
- Migration path and reasoning behind choices available
- Spread spectrum: Frequency Hopping, Direct Sequence CDMA, RAKE receiver, IS-95 CDMA uplink and downlink example, receiver block diagram
- System metrics: BER, SNR, Eb/No definitions
Radio Propagation Characterization
- AWGN channel
- Rayleigh/Rician multipath fading
- Mathematical background
- Practical explanation
- Delay spread concept (flat vs. frequency selective fading)
- Indoor and outdoor propagation measurements
- Delay spread and coherence bandwidth (outdoor and indoor)
- Log normal shadowing
- Path loss models (Free Space, Hata, Cost231, Walfish-Bertoni, etc.)
- Micro/Macro cell measurements
- Comparison of worldwide measurements.
- Man-made interference
- Co-Channel interference (CCI)
- Adjacent Channel interference (ACI)
- Correlation of frequency and time
- Simulating multipath fading channels: Jakes, LPF-ing, etc.
Performance Improvement Techniques
- Forward Error Correction (FEC)
- Block (linear codes, encoder, syndrome decoding)
- Convolutional (trellis diagram, Viterbi algorithm, punctured coding)
- Turbo (encoder and decoder)
- Interleaver/de-interleaver – advantages and disadvantages
- Antenna receiver diversity techniques: Switching, Equal Gain, Maximal Ratio, Optimal Combining
- Theoretical SNR improvement
- Expected BER performance
- Antenna transmit diversity techniques: Space Time Block Codes, Closed Loop Antenna Arrays, MIMO
CDMA2000 System Components (Building Blocks)
- System goals (latency, throughput, etc.)
- CDMA200 Release A, B and C overview
- Mobile Station State Definition
- CDMA 1xRTT physical channels (UL and DL)
- Logical channels (UL and DL)
- Protocol overview (Layer 1 – PHY, Layer 2- MAC, Layer 3- RLC functions)
- 1xEV-DO Release A, B and C overview
- 1xEV-DO physical channels
- Access Terminal State Definition
- 1xEV-DO logical channels
- PN sequences discussion: m sequences, Gold codes, Walsh
- Spreader and despreader (Complex and Quadrature)
- RAKE receiver
CDMA2000 System Scenarios
- Echo profile manager (searcher)
- PN time tracking and acquisition
- Paging discussion
- Power control
- Uplink and downlink
- Comparison to IS-95
- Multi-user scenarios
- Pilot symbol aided coherent detection
- Channel estimation
- QPSK vs. BPSK pilot symbols
- Variable processing gain
- Cell search and handoffs
- Channel assignment
- Traffic channel and radio configurations
- UL/DL performance
- Available data rates
- Multicode transmission
- Receiver implications
- Network architecture (BTS, BSC, CN)
- Migration from circuit-switched to packet based systems
- Comparison with WCDMA system scenarios
3GPP WCDMA System Components (Building Blocks)
- System goals (latency, throughput, etc.)
- 3GPP Release Overview (Release 99 to Release 8 features)
- WCDMA physical channels
- UE state definitions
- WCDMA logical channels
- WCDMA protocol overview (Layer1-PHY, Layer2-MAC, Layer3-RLC functions)
- High-speed Downlink Packet Access (HSDPA) overview
- HSDPA physical channels
- High-speed Uplink Packet Access (HSUPA) overview
- HSUPA physical channels
- PN sequences discussion: m sequences, Gold codes, OVSF
- Spreader and despreader
- RAKE receiver: Overall block diagram discussion
- RAKE receiver: Signal processing
- Channel estimation (multi-slot averaging)
- PN code time tracking (DLL, TDL)
- AFC (two types)
- AGC
- DC offset
- Modulation comparison
- Searcher and finger management
3GPP WCDMA System Scenarios
- Echo profile manager (searcher)
- PN time tracking and acquisition
- SIR power control
- Inner, Outer, and Closed Loop
- UL and DL Closed Loop comparison
- Performance improvement
- Multi-user scenario
- Pilot symbol aided coherent detection
- Channel estimation
- QPSK vs. BPSK pilot symbols
- Rate matching
- Variable processing gain
- Modulation (HPSK) and filtering
- Cell search and handoffs
- Intra-frequency measurements
- Paging discussion
- Comparison of IS-95, CDMA2000 and WCDMA paging protocols
- Power consumption conclusion
- Channel assignment
- Call flow diagrams
- Mobile originated
- Mobile terminated
- HSDPA performance results
- Available data rates
- Multicode transmission
- Receiver implications
- Performance
- Network architecture (NodeB, Radio Network Controller – RNC, Core Network -CN)
- Partitioning of protocol stack across network
- Access Stratum (AS) and Non-Access Stratum (NAS)
- Migration from circuit-switched to packet based systems
- What needs to change on the 3G systems to support this migration?
- Comparison with CDMA2000 system scenarios
- System architecture
- Ciphering examples
- Integrity protection
- Confidentiality
- WCDMA and HSDPA examples
Link Budget and System Capacity Examples
- Link budget methodology
- Link budget equations
- Rise over Thermal calculations
- Example for indoors and outdoors (Excel spreadsheets)
- Cell capacity example
- Targeted frequency bands
Course Wrap-up: Recap and Discussion