WIRELESS COMMUNICATIONS EX 765 04
Lecture : 3
Tutorial : 1
Practical : 3/2
Course Objectives:
To introduce the principles and building blocks of wireless communications.
- Introduction
(2 hours)
- Evolution of wireless (mobile) communications, worldwide market, examples
- Comparison of available wireless systems, trends
- Trends in cellular radio (2G, 2.5G, 3G, beyond 3G) and personal wireless communication systems
- Cellular mobile communication concept
(4 hours)
- Frequency re-use and channel assignment strategies
- Handoff strategies, types, priorities, practical considerations
- Interference and system capacity, co-channel and adjacent channel interference, power control measures
- Grade of service, definition, standards
- Coverage and capacity enhancement in cellular network, cell splitting, sectoring, repeaters, microcells
- Radio wave propagation in mobile network environment
(12 hours)
- ReviewFree space propagation model, radiated power and electric field
- ReviewPropagation mechanisms (large-scale path loss) - Reflection, ground reflection, diffraction and scattering
- Practical link budget design using path loss models.
- Outdoor propagation models (Longley-Rice, Okumura, Hata, Walfisch and Bertoni, microcell)
- Indoor propagation models (partition losses, long-distance path loss, multiple breakpoint, attenuation factor)
- Small scale fading and multipath (factors, Doppler shift), Impulse response model of multipath channel, multipath measurements, parameters of mobile multipath channel (time dispersion, coherence bandwidth, Doppler spread and coherence time)
- Types of small-scale fading (flat, frequency selective, fast, slow), Rayleigh and Ricean fading distribution
- Modulation-Demodulation methods in mobile communications
(4 hours)
- Review of amplitude (DSB, SSB, VSB) and angle (frequency, phase) modulations and demodulation techniques
- Review of line coding, digital linear(BPSK, DPSK, QPSKs) and constant envelop (BFSK, MSK, GMSK) modulation and demodulation techniques
- M-ary (MPSK, MFSK, QAM and OFDM) modulation and demodulation techniques
- Spread spectrum modulation techniques, PN sequences, direct sequence and frequency hopped spread spectrums
- Performance comparison of modulations techniques in various fading channels
- Equalization and diversity techniques
(4 hours)
- Basics of equalization. Equalization in communications receivers, linear equalizers
- Non-linear equalization, decision feedback and maximum likelihood sequence estimation equalizations
- Adaptive equalization algorithms, zero forcing, least mean square, recursive least squares algorithms, fractionally spaced equalizers
- Diversity methods, advantages of diversity, basic definitions
- Space diversity, reception methods (selection, feedback, maximum ratio and equal gain diversity)
- Polarization, frequency and time diversity
- RAKE receivers and interleaving
- Speech and channel coding fundamentals
(4 hours)
- Characteristics of speech signals, frequency domain coding of speech (sub-band and adaptive transform coding)
- Vocoders (channel, formant, cepstrum and voice-excited ), Linear predictive coders (multipulse, code and residual excited LPCs), Codec for GSM mobile standard
- Review of block codes, Hamming, Hadamard, Golay, Cyclic, Bosh-Chaudhary- Hocquenghgem (BCH), Reed-Solomon (RS) codes
- Convolutional codes, encoders, coding gain, decoding algorithms (Viterbi and others)
- Trellis Code Modulation (TCM), Turbo codes
- Multiple Access in Wireless communications
(9 hours)
- Frequency Division Multiple Access (FDMA), principles and applications
- Time Division Multiple Access (TDMA), principles and applications
- Spread Spectrum Multiple Access, Frequency Hopped Multiple Access, Code Division Multiple Access, hybrid spread spectrum multiple access techniques
- Space Division Multiple Access
- Standards for Wireless Local Area Networks
- Wireless systems and standards
(6 hours)
- Evolution of wireless telephone systems: AMPS, PHS, DECT, CT2, IS-94, PACS, IS-95, IS-136, IS-54 etc.
- Global system for Mobile (GSM): Services and features, system architecture, radio sub-system, channel types (traffic and control), frame structure, signal processing, example of a GSM call
- CDMA standards: Frequency and channel specifications, Forward and Reverse CDMA channels
- WiFi, WiMAX, UMB, UMTS, CDMA-EVDO, LTE, and recent trends
- Regulatory issues (spectrum allocation, spectrum pricing,licensing, tariff regulation and interconnection issues)
Practical:
- Case Study and Field Visit
- Visits to mobile service operators, network service providers, internet service providers
References:
- K. Feher, "Wireless Digital Communications"
- T. Rappaport, "Wireless Communications"
- J. Schiller, "Mobile Communications"
- Leon Couch, "Digital and analog communication systems"
- B.P.Lathi," Analog and Digital communication systems"
- J. Proakis, "Digital communication systems"
- D. Sharma, Course manual "Communication Systems II".
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