Dynamic spectrum management in packet networks

新的通信技术和服务创造了对电磁频谱的爆炸性需求。无线电频谱是一种有限的资源，其使用是由政府授权的。传统上，频谱分配基于固定的长期频段分配模式，并不一定确保在所有时间、所有地区最有效地使用频谱。为了更有效地利用未使用的频谱，该提案寻求设计适应快速变化的网络条件的通信系统。将考虑网络中不同级别的合作和竞争。这项建议中调查的频谱的创新使用将有助于监管机构和服务提供商为公众提供更大的无线互联网接入容量。拟议研究的战略计划包括开发分布式多层算法，用于在具有受全球资源约束的可变容量的网络中进行联合媒体访问控制和资源分配。将制定共同优化端到端速率和资源分配的协议，以最大限度地提高总网络和频谱利用率。具体地说，这项提议旨在解决无线电网络中的技术问题，例如(I)多址衰落信道；(Ii)随机分组到达和时频分配；(Iii)实时传输中的能量/延迟权衡；以及(Iv)端到端性能管理。申请人最近提出的多小波包调制(MWPM)方案推广了认知无线电系统中提出的用于自适应的正交频分复用(Ofdm)方案。研究将建立在MWPM作为多址接入方案的基础上，该方案提供了灵活的时间-频率平铺的时间频谱。这项研究将影响新的无线网络体系结构的发展方向，并将适用于任何无线电系统，从无线到有线调制解调器，实施自适应调制方案和跨层网络协议设计。

New communications technologies and services have created an explosive demand for electromagnetic spectrum. The radio spectrum is a limited resource, the use of which is licensed by governments. Traditionally, spectrum allocations are based around the paradigm of fixed long-term frequency band assignments and do not necessarily ensure spectrum is being used most efficiently at all times, in all areas. To exploit unused spectrum more efficiently, this proposal seeks to design communication systems that adapt to rapidly changing network conditions. Different levels of cooperation and competition in the network will be considered. Innovative use of spectrum investigated in this proposal will aid regulatory bodies as well as service providers in supplying the public with increased capacity for wireless Internet access. The strategic plan for the proposed research involves the development of distributed, multi-layer algorithms for joint medium access control and resource allocation in networks with variable capacities subject to a global resource constraint. Protocols will be devised that jointly optimize end-to-end rates and resource allocation to maximize total network and spectrum utility. Specifically, this proposal aims to address technical issues in radio networks, such as (i) multi-access fading channels; (ii) random packet arrivals and time-frequency allocations; (iii) energy/delay tradeoff in real-time transmissions; and (iv) end-to-end performance management. The multi-wavelet packet modulation (MWPM), introduced recently by the applicant, generalizes orthogonal frequency division multiplexing (OFDM) schemes proposed for adaptation in cognitive radio systems. The investigations will build on the MWPM as the multiple access scheme which provides flexible time-frequency tiling of the temporal spectrum. The research will impact the direction of the development of new radio network architectures and will be applicable to any radio system, from wireless to cable modems, implementing adaptive modulation schemes and the cross-layer network protocol design.