Baseband analog front-end and digital back-end for reconfigurable multi-standard terminals

Multimedia applications are driving wireless network operators to add high-speed data services such as Edge (E-GPRS), WCDMA (UMTS) and WLAN (IEEE 802.11a,b,g) to the existing GSM network. This creates the need for multi-mode cellular handsets that support a wide range of communication standards, each with a different RF frequency, signal bandwidth, modulation scheme etc. This in turn generates several design challenges for the analog and digital building blocks of the physical layer. In addition to the above-mentioned protocols, mobile devices often include Bluetooth, GPS, FM-radio and TV services that can work concurrently with data and voice communication. Multi-mode, multi-band, and multi-standard mobile terminals must satisfy all these different requirements. Sharing and/or switching transceiver building blocks in these handsets is mandatory in order to extend battery life and/or reduce cost. Only adaptive circuits that are able to reconfigure themselves within the handover time can meet the design requirements of a single receiver or transmitter covering all the different standards while ensuring seamless inter-interoperability. This paper presents analog and digital base-band circuits that are able to support GSM (with Edge), WCDMA (UMTS), WLAN and Bluetooth using reconfigurable building blocks. The blocks can trade off power consumption for performance on the fly, depending on the standard to be supported and the required QoS (Quality of Service) leve

A multilayeredly rolled inverted-F antenna for dual-band mobile phones.

Lam, Fuk Ming.Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.Includes bibliographical references.Abstracts in English and Chinese.Abstract --- p.IAcknowledgements --- p.VTable of Contents --- p.VIList of Figures --- p.IXList of Tables --- p.XVIChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Background --- p.1Chapter 1.2 --- Overview of the Work --- p.5Chapter 1.3 --- Original contribution of this thesis --- p.6Chapter 1.4 --- Organization of this thesis --- p.7Chapter 1.5 --- Remarks on frequency dependent parameters in this thesis --- p.8Reference --- p.9Chapter Chapter 2 --- Small Antennas for mobile phone applications --- p.10Chapter 2.1 --- Introduction --- p.10Chapter 2.2 --- Definitions --- p.11Chapter 2.2.1 --- Quality factor --- p.11Chapter 2.2.2 --- Efficiency --- p.12Chapter 2.2.3 --- Return Loss and impedance bandwidth --- p.12Chapter 2.2.4 --- Antenna gain and radiation pattern --- p.13Chapter 2.3 --- Fundamental limitations of small antenna --- p.14Chapter 2.4 --- Low-profile and Dual-band techniques --- p.16Chapter 2.4.1 --- Inverted-L/F and Planar Inverted-F Antenna --- p.16Chapter 2.4.2 --- Dual-band PIFA --- p.21Chapter 2.4.3 --- Discussion on miniaturization of mobile phone antenna --- p.23Chapter 2.5 --- Ground plane effect of mobile phone antenna --- p.26Chapter 2.5.1 --- Optimal location to excite antenna over a finite ground plane --- p.26Chapter 2.5.2 --- Dependence of resonant frequency and impedance bandwidth on ground plane length --- p.27Chapter 2.5.3 --- Dual-resonator model for mobile phone antenna --- p.32Chapter 2.6 --- Summary --- p.38Reference --- p.38Chapter Chapter 3 --- A Multilayeredly Rolled Inverted-F Antenna for Dual-band Mobile Phones --- p.42Chapter 3.1 --- Introduction --- p.42Chapter 3.2 --- Literature review on rolled antennas --- p.43Chapter 3.3 --- Proposed MRIFA --- p.47Chapter 3.3.1 --- Antenna configuration --- p.47Chapter 3.3.2 --- Simulation studies --- p.51Chapter 3.3.3 --- Prototype and Experimental results --- p.59Chapter 3.3.4 --- Comparison with a reference PIFA --- p.66Chapter 3.4 --- Mobile phone installed with the MRIFA --- p.70Chapter 3.5 --- Summary --- p.80Reference --- p.81Chapter Chapter 4 --- A fast method to evaluate Total Isotropic Sensitivity (TIS) in mobile phone active measurement --- p.82Chapter 4.1 --- Introduction --- p.82Chapter 4.2 --- Proposed fast method for TIS evaluation --- p.85Chapter 4.2.1 --- Observed relationship between total Effective Isotropic Radiated Power (EIRP) and total Effective Isotropic Sensitivity (EIS) --- p.85Chapter 4.2.2 --- EIS's estimation from EIRPs for TIS evaluation --- p.89Chapter 4.3 --- Summary --- p.92Reference --- p.93Chapter Chapter 5 --- Conclusion --- p.94List of Publications --- p.96Appendix A - Details of sample mobile phones investigated in this thesis research --- p.97Appendix B - Active measurement of mobile phone's transmit power and receiver sensitivity --- p.107Appendix C - MRIFA realization procedure --- p.11

Modelling and performances assessment of OFDM and fast-OFDM wireless communication systems.

This thesis is mainly concerned with the design, modelling and performance assessment of modulation techniques for use in wireless communication systems. The work is divided, broadly in three areas; a multimode system proposal, an assessment of a new modulation scheme and a system optimisation technique. A multimode system architecture employing GSM and EDGE systems and an Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The OFDM system is designed to have similar frame structure, channel allocation and spectrum shape to those of the GSM and EDGE systems. The multimode system is evaluated under typical multipath fading environments specified for GSM/EDGE and adjacent-channel and co-channel interference. The results indicated that the proposed OFDM system can be perfectly integrated within the GSM/EDGE network core. Furthermore, a novel modulation technique is investigated. Fast-OFDM (FOFDM) is a variation of OFDM, which offers twice the bandwidth efficiency when compared to OFDM. However, the bandwidth efficiency only applies to one dimensional modulation schemes (BPSK or M-ASK). The suitability of FOFDM for wireless communications is assessed by studying its performance under receiver front-end distortions and multipath fading environments. The performance of the FOFDM system is compared with the performance of a similar OFDM system. The results indicated that under small distortion conditions, the performance of FOFDM and OFDM is comparable. Finally, the effect of interpolation filtering on OFDM systems in noise limited and interference limited environments is investigated. The aim of this study is to highlight that interference should be taken into consideration when designing systems for wireless communications. In addition, this study can be utilised in software defined radio schemes, offering optimised performance. Overall, this thesis presents work over a range of research areas, providing system proposals, modulation comparisons and system optimisation techniques that can be used by developers of future mobile systems