ABSTRACT
Contents 14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 14.2 Common Architecture for Dynamic Spectrum Accessing
in Heterogeneous Networking Environment. . . . . . . . . . . . . . . . . . . . . . 357 14.3 Transmitter-centric Spectrum-Agile Waveform Adaptation:
Matching with UWB Spectral Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 14.4 Transmit Power Control and Optimization
in Ultra-wideband Cognitive Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 14.4.1 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 14.4.2 Transmit Power Allocation Schemes . . . . . . . . . . . . . . . . . . . . . 369
14.4.2.1 Optimal Power Allocation for Channel Data Throughput Improvement. . . . . . . . . . . . . . . . . . . . . . 369
14.4.2.2 Optimal Power Allocation for BER Performance Improvement . . . . . . . . . . . . . . . . . . . . . 372
14.4.3 Simulation Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . 376 14.5 Receiver-Centric Spectrum-Agile Waveforms Adaptation:
Matching with Interference Temperature Limit . . . . . . . . . . . . . . . . . . . 378
14.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
This chapter describes the concept and approach of ultra-wideband cognitive radio (CR-UWB), a wireless technique based on UWB transmission able to self-adapt to the characteristics of the surrounding wireless communications environment. A novel strategy to exploit the advantages and features of integrating cognitive radio (CR) with the UWB technology is investigated with an aim of exploring UWB radio as an enabling technology for implementing cognitive radio. In particular, dynamic spectrum accessing and sharing based upon the spectrum agility and adaptation flexibility is proposed. At first, a common architecture supported by CR-UWB corresponding to heterogeneous networking scenarios is illustrated. Then, a number of concrete technical methods for generation of the transmittercentric spectrum-agile waveforms, which take advantage of the adaptive combination of a set of orthogonal UWB pulse waveforms complying with the FCC spectral mask at the transmitter side, are discussed. Furthermore, various transmit power control and optimization schemes for improving the system capacity as well as the bit-error-rate (BER) performance are derived. Finally, the receiver-centric spectrum-agile waveform adaptation, which is characterized by generating the spectrum-agile UWB waveforms complying with the receiving interference limit rather than the FCC spectral mask is analyzed.
