Energy-saving Technologies Of WLAN System And Energy-saving Algorithms Of Digitally Dc-dc Converters

In recent years, the application region of WLAN hotspots continues to expand, and the effect covered by signal also increases significantly, accompanied by a surge of AP energy consumption. When we design WLAN network architectures and AP equipments we don’t fully consider the problem of energy saving, and we only take the signal strength and coverage area as the main targets. Now we must take energy saving into account. For a long time, the field of the power supply has been dominated by the analog solutions, while people have tried to design power products with digital technology since the performance-price ratio of digital circuits (such as MCU and DSP) is increasingly becoming attractive. Owing to the splendid work finished in the last several years, the digital power products have become more and more attractive and have had several unique features not being owned by any traditional analog products. Since digital technology has been employed in the design of power supplies, the digital power supply will appear in markets in the near future.The content of this thesis focuses on the following aspects:In the aspect of network construction, the design of WLAN network architecture with energy saving is discussed; In the aspect of AP equipments, energy-saving strategies for AP’s internal modules are given after introducing the adaptive digital power technology, and the algorithm in the application of AP’s direct current converter to achieve optimal conversion efficiency is realized; In the aspect of digital power, a digitally controlled dc-dc converter with least module loss is designed, which is the most important part of the digital power supply.Innovations of the paper include the following five aspects:Firstly, the paper discusses in detail the existing WLAN network architecture, presents four kinds of energy-saving strategies for the network, gives the corresponding algorithms and the implementation process, and validates theeffectiveness of the energy saving. Secondly, the paper innovatively proposes a modelfor evaluating the energy consumption level of AP, whichhas been widely adopted by Chinese operators and is regarded as an important evaluation method of energy saving in AP network access test. Thirdly, the paper considers the trade-off in realizing the maximization of the conversion efficiency under heavy loads and light loads. Based on this constraint, the realization of the optimization of the efficiency curve in a specified AP application case is given and experimental results are also given to verify the effectiveness of the efficiency optimization strategies in the paper. Fourthly, the digital loop DC-DC converter is introduced to the traditional AP module, and the paper presents an energy saving algorithm of digital control for AP, proposes a monolithic digitally controlled buck converter with a time-to-digital converter based ADC (TDC-based ADC) sharing delay cells with a digital pulse-width modulator (DPWM). The delay cells in high resolution DPWM are employed as the time reference for the TDC-based ADC, which eliminates the need for an independent delay line. The ADC has a large dynamic range with no penalty of increase of power consumption, which is suitable for sophisticated controls requiring a large ADC dynamic range. A digitally controlled buck converter with such shared delay cells is designed and fabricated in SMIC0.13um process. Fifthly, the paper introduces adaptive digital power supply module to traditional AP, establishes the energy consumption models for AP’s modules."Energy-saving model for the core module"is established according to the temperature information,"energy-saving model for the ethernet module" is established according to the duty ratio information, and "energy-saving model for the RF module" is established according to the error rate information, and the paper finally gives the implementation scheme of the chip.