A New Low Complexity Uniform Filter Bank Based on the Improved Coefficient Decimation Method

In this paper, we propose a new uniform filter bank (FB) based on the improved coefficient decimation method (ICDM). In the proposed FB’s design, the ICDM is used to obtain different multi-band frequency responses using a single lowpass prototype filter. The desired subbands are individually obtained from these multi-band frequency responses by using low order frequency response masking filters and their corresponding ICDM output frequency responses. We show that the proposed FB is a very low complexity alternative to the other FBs in literature, especially the widely used discrete Fourier transform based FB (DFTFB) and the CDM based FB (CDFB). The proposed FB can have a higher number of subbands with twice the center frequency resolution when compared with the CDFB and DFTFB. Design example and implementation results show that our FB achieves 86.59% and 58.84% reductions in resource utilizations and 76.95% and 47.09% reductions in power consumptions when compared with the DFTFB and CDFB respectively

Wideband TV white space transceiver design and implementation

For transceivers operating in television white space (TVWS), frequency agility and strict spectral mask fulfilments are vital. In the UK, TVWS covers a 320 MHz wide frequency band in the UHF range, and the aim of this paper is to present a wideband digital up- and down converter for this scenario. Sampling at radio frequency (RF), a two stage digital conversion is presented, which consists of a polyphase filter for implicit upsampling and decimation, and a filter bank-based multicarrier approach to resolve the 8MHz channels within the TVWS band. We demonstrate that the up- and down-conversion of 40 such channels is hardly more costly than that of a single channel. Appropriate filter design can satisfy the mandated spectral mask and control the reconstruction error. An FPGA implementation is discussed, capable of running the wideband transceiver on a single Virtex-7 device with sufficient word length to preserve the spectral mask requirements of the system

Behavioral modeling for sampling receiver and baseband in Software-Defined Radio

Projecte realitzat en col.laboració amb Illinois Institute of TechnologySoftware Defined-Radio (SDR) consists of a wireless communication in which the transmitter and the receiver are controlled by means of software. Its ultimate goal is to provide a single universal radio transceiver capable of multi-mode multi-standard wireless communications. Modeling of the proper circuits and new designs aimed at SDR is necessary for further development and experimentation. It sharpens our understanding of fundamental processes, helps to make decisions and provides a guide for training exercises. Due to the lack of these models two independent and different models have been created based on new proposed designs. Each modeled design belongs to a different layer of abstraction and therefore, the tool used is different as well. The first proposed model consist of a Simulink (Matlab) file which models the discrete-time signal processing used in a Discrete-time receiver for Bluetooth Radio. The results show good performance when processing a signal that has been transmitted through a noisy channel. The signal at each step is visualized to see the individual effect of each building block. The second proposed model narrows down the topic and focuses on a Widely-tunable, Reconfigurable Analog Baseband filter, for which a Verilog-A model, by using Cadence, has been created. The outstanding feature of the filter is that its programmability is based on the duty-cycle of the input control signals. Moreover, Verilog-A modules bring the design really close to the real circuit, allowing the designer to face problems that the real circuit will present and easing the replacement of the building blocks with new ones when desired. The results for this model show a very little error within the passband of the filter that increases when the attenuation introduced for the stopband becomes higher

Efficient Fast-Convolution-Based Waveform Processing for 5G Physical Layer

This paper investigates the application of fast-convolution (FC) filtering schemes for flexible and effective waveform generation and processing in the fifth generation (5G) systems. FC-based filtering is presented as a generic multimode waveform processing engine while, following the progress of 5G new radio standardization in the Third-Generation Partnership Project, the main focus is on efficient generation and processing of subband-filtered cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM) signals. First, a matrix model for analyzing FC filter processing responses is presented and used for designing optimized multiplexing of filtered groups of CP-OFDM physical resource blocks (PRBs) in a spectrally well-localized manner, i.e., with narrow guardbands. Subband filtering is able to suppress interference leakage between adjacent subbands, thus supporting independent waveform parametrization and different numerologies for different groups of PRBs, as well as asynchronous multiuser operation in uplink. These are central ingredients in the 5G waveform developments, particularly at sub-6-GHz bands. The FC filter optimization criterion is passband error vector magnitude minimization subject to a given subband band-limitation constraint. Optimized designs with different guardband widths, PRB group sizes, and essential design parameters are compared in terms of interference levels and implementation complexity. Finally, extensive coded 5G radio link simulation results are presented to compare the proposed approach with other subband-filtered CP-OFDM schemes and time-domain windowing methods, considering cases with different numerologies or asynchronous transmissions in adjacent subbands. Also the feasibility of using independent transmitter and receiver processing for CP-OFDM spectrum control is demonstrated