Multi-standard adaptive wireless communication receivers: adaptive applications mapped on heterogeneous dynamically reconfigurable hardware

摘要

Today the world is overwhelmed with portable devices like handheld computers, mobile telephones and portable navigation systems. These devices will eventually be integrated into multi-functional devices that can perform all kinds of functions in one single system. Ultimately, portable devices will exist that can perform a wide variety of functions and provide rich information to the user. One of the challenges for implementing these integrated multi-functional devices is to define a hardware architecture that is powerful enough to process complex algorithms, flexible enough to process all kinds of algorithms, and energy efficient enough because the portable devices are battery-powered. This work focuses on the implementation of adaptive multi-standard multi-mode wireless communication systems that are implemented on dynamically reconfigurable hardware. The coarse-grained reconfigurable MONTIUM architecture is used to illustrate the mapping of wireless communication standards. Based on the mapping of different wireless communication algorithms, modifications of the MONTIUM architecture have been proposed. Baseband processing and channel decoding of different wireless communication systems have been investigated. Orthogonal Frequency Division Multiplexing (OFDM) and Wideband CDMA (WCDMA) wireless communication techniques have been mapped on dynamically reconfigurable System-on-Chip (SoC) architecture that contains several MONTIUM Tile Processors (TPs). We showed that a single heterogeneous reconfigurable SoC platform can support various standards with a performance similar to an Application Specific Integrated Circuit (ASIC) implementation. The digital baseband processing of a HiperLAN/2 receiver and an Universal Mobile Telecommunications System (UMTS) receiver were mapped on MONTIUM TPs. Furthermore, the Viterbi and Turbo decoder algorithms were mapped on the same reconfigurable hardware. All implementations of the baseband processing and channel decoding algorithms that are mapped on the MONTIUM TP have been verified against floating-point reference models. Performance simulations on the implemented algorithms show hardly any difference in accuracy between the floating-point reference models and the MONTIUM-based implementations. As expected, an ASIC implementation of the algorithms is more energy efficient than an implementation in reconfigurable hardware. However, the ASIC implementation is fixed and the functionality of the ASIC cannot be changed. The power consumption and the configuration size of the MONTIUM TP depends on the implemented Digital Signal Processing (DSP) algorithms. The normalized dynamic power consumption of the MONTIUM-based Rake receiver in 0.13 μm CMOS technology is estimated at 0.470 mW/MHz. For the Viterbi decoder, the normalized dynamic power consumption is estimated at 0.309 mW/MHz on the same MONTIUM architecture. The configuration sizes of the different DSP algorithms implemented on theMONTIUM TP are typically about 1 kB of configuration data. The MONTIUM TP can typically be configured as Rake or HiperLAN/2 receiver in less than 5 μs. In 7 μs the MONTIUM TP is configured as Viterbi or Turbo decoder. The characteristics of the algorithms can be semi-instantly changed through partial reconfiguration of the MONTIUM TP in the order of nanoseconds. The small configuration sizes of the MONTIUM-based algorithms enable new opportunities for implementing real-adaptive applications. The standards level of adaptivity allows the terminal to adapt the communication standard that is used to satisfy the Quality of Service (QoS) requirements and the wireless channel conditions at a certain location. The algorithm-selection level of adaptivity allows the terminal to select the algorithms that satisfy the QoS requirements in the given communication environment in the most efficient manner. The algorithm-parameter level of adaptivity allows the terminal to change the parameters of a specific algorithm. Exploiting the different kinds of adaptivity results in energy efficient wireless communication receivers that are capable of adapting the radio to the required QoS in different wireless communication environments. The flexibility, performance and low configuration overhead of the coarse-grained reconfigurable MONTIUM architecture enables the implementation of real-adaptive wireless communication receivers, which can switch their functionality instantly.