Adaptive channel-superframe allocation (ACSA) for 20 GHz wireless networks

Millimeter-wave (MMW) systems are high frequency wireless systems with a center frequency of around 60 GHz. This thesis deals with adaptive channel-superframe allocation (ACSA) for such system. An adaptive bandwidth or channel allocation algorithm is utilized in the piconet controller (PNC) and a new superframe structure is designed in order to distribute bandwidth among real-time (RT) and non-real-time (NRT) flows. We propose to serve RT and NRT flows separately in different channels instead of serving them in different times. We also propose to 'change the sliced superframe of IEEE 802.15.3 to an adaptive unsliced superframe in order to decrease the TCP round-trip time. We simulated a MMW system with appropriate parameters using 802.15.3 MAC as well as ACSA MAC. We meaSured three performance metrics (throughput, delay and fairness), which we aimed to improve in our superframe design. The simulation results show that the adaptive superframe structure . could provide' throughput improvements not only for NRT flows, but also for RT flows. The control algorithm in PNC could manage the bandwidth allocation in superframe and improve the throughput of RT flows. The channel access delay is improved by providing an unsliced superframe, which eliminated an imposed delay on TCP connections. Finally, the better distribution of bandwidth in ACSA MAC improves the fairness of the system. As a brief, the simulation results support the analysis of the proposed adaptive channelsuperframe allocation algorithm, which could generally improve the quality of service for MMW systems.

Adaptive channel-superframe allocation (ACSA) for 20 GHz wireless networks

Millimeter-wave (MMW) systems are high frequency wireless systems with a center frequency of around 60 GHz. This thesis deals with adaptive channel-superframe allocation (ACSA) for such system. An adaptive bandwidth or channel allocation algorithm is utilized in the piconet controller (PNC) and a new superframe structure is designed in order to distribute bandwidth among real-time (RT) and non-real-time (NRT) flows. We propose to serve RT and NRT flows separately in different channels instead of serving them in different times. We also propose to 'change the sliced superframe of IEEE 802.15.3 to an adaptive unsliced superframe in order to decrease the TCP round-trip time. We simulated a MMW system with appropriate parameters using 802.15.3 MAC as well as ACSA MAC. We meaSured three performance metrics (throughput, delay and fairness), which we aimed to improve in our superframe design. The simulation results show that the adaptive superframe structure . could provide' throughput improvements not only for NRT flows, but also for RT flows. The control algorithm in PNC could manage the bandwidth allocation in superframe and improve the throughput of RT flows. The channel access delay is improved by providing an unsliced superframe, which eliminated an imposed delay on TCP connections. Finally, the better distribution of bandwidth in ACSA MAC improves the fairness of the system. As a brief, the simulation results support the analysis of the proposed adaptive channelsuperframe allocation algorithm, which could generally improve the quality of service for MMW systems.

Design Issues for Multi-Mode Multi-Standard Transceivers

Multi-mode and multi-band transceivers, i.e., transceivers with the capability to operate in different frequency bands and to support different waveforms and signaling schemes, are objects of intense study. In fact, hardware reuse among different standards would help to reduce production costs, power consumption, and to increase the integration level of a given implementation. The design of such transceivers is indeed very complex, because it not only implies the choice of the architecture more suitable for the target application, but also the choice and the design of reconfigurable building blocks to perform tuning among the different standards and signaling schemes. In addition, different standards may have considerably different requirements in terms of receiver sensitivity, linearity, input dynamic range, error vector magnitude (EVM), signal bandwidth, and data rate, which in turn make the design of a multi-mode reconfigurable transceiver a very challenging task. In this chapter, the authors present the most common techniques and architecture schemes used in modern wireless communication systems supporting standards for cellular, wireless local area networks (WLAN), and wireless personal area networks (WPAN), i.e., GSM, WCDMA, IEEE 802.11 (Wi-Fi), IEEE 802.15.1 (Bluetooth), IEEE 802.15.4 (Zigbee), and IEEE 802.15.3 (UWB). State-of-the-art techniques for multi-standard cellular, WLAN, and WPAN transceivers are thoroughly analyzed and reviewed with special emphasis on those relying on bandpass sampling and multi-rate signal processing schemes.