The next evolution in cellular communications will not only improve upon the performance of previous generations, but also represent an unparalleled expansion in the number of services and use cases. One of the foundations for this evolution is the design of highly flexible, versatile, and resource-/power-efficient hardware components. This paper proposes and evaluates an FPGA-oriented baseband processing architecture suitable for communication scenarios such as non-contiguous carrier aggregation, centralized Cloud Radio Access Network (C-RAN) processing, and 4G/5G waveform coexistence. Our system is upgradeable, resource-efficient, cost-effective, and provides support for three 5G waveform candidates. Exploring Dynamic Partial Reconfiguration (DPR), the proposed architecture expands the design space exploration beyond the available hardware resources on the Zynq xc7z020 through hardware virtualization. Additionally, Dynamic Frequency Scaling (DFS) allows for run-time adjustment of processing throughput and reduces power consumption up to 88%. The resource overhead for DPR and DFS is residual, and the reconfiguration latency is two orders of magnitude below the control plane latency requirements proposed for 5G communications.waveforms (FBMC, UFMC, GFDM) intermingled with a variety of 3G and 4G waveforms" [3]. In heavily used portions of the spectrum, such as the sub-6 GHz band, multi-waveform coexistence requires Dynamic Spectrum Access (DSA) and Carrier Aggregation (CA) techniques to achieve a more efficient spectrum utilization [1].Other important factors in 5G NR are cost minimization and energy efficiency. Cloud Radio Access Networks (C-RANs) attempt to achieve a more efficient energy consumption and resource allocation by deploying a central Baseband processing Unit (BBU) that serves multiple Remote Radio Heads (RRHs) [4]. This network architecture relies on reconfigurable hardware modules to implement BBUs supporting the different access technologies and modes of operation used by RRHs.The realization of the 5G vision will strongly rely on the design of hardware infrastructure adjusted to the challenges imposed by future wireless communications. Regarding digital baseband processing, hardware designs should be: (1)flexible to support multiple services requirements, waveforms, and numerologies; (2) evolvable/forward-compatible to be easily upgradeable with new functionalities and future modes of operation, thus extending the system's duty lifetime; (3) energy-efficient and (4) cost-effective. FPGAs are convenient platforms to design systems with these characteristics. Apart from their capacity for parallel intensive computation, FPGAs feature a high degree of flexibility not only at design time, but also at runtime, through Dynamic Partial Reconfiguration (DPR) [5]: the ability to reconfigure portions of FPGA logic fabric (reconfigurable regions) while the other portions remain unchanged and running. This increases the FPGA functional density, as mutually-exclusive circuits/functionalities are implemented o...

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Cognitive Radios (CR) are viewed as a solution for spectrum utilization and management in next generation wireless networks. In order to adapt themselves to the actual communications environment, CR devices require highly flexible baseband processing engines. One of the most relevant operations involved in radio baseband processing is the FFT. This work presents a reconfigurable FFT processor supporting FFT sizes and throughputs required by the most used wireless communication standards. By employing Dynamic Partial Reconfiguration (DPR), the implemented design can adapt the FFT size at run-time and specialize its operation to the immediate communication demands. This translates to hardware savings, enhanced resource usage efficiency and possible power savings. The results obtained for reconfiguration times suggest that DPR techniques are a viable option for designing flexible and adaptable baseband processing components for CR devices.