FPGA Signal Preprocessing for Digital Wireless Receivers | Bjarne Petersen
| | Abstract | This thesis deals with the task of exchanging analog f ilters with digital filters. These analog fi lters, used in a base station receiver for wireless communication, have the job of fi ltering incoming TETRA and TEDS signals for unwanted channels and blockers. Analysis performed in this thesis based on a set of requirements for the filter process, have concluded that the best filter type for the digital filter is FIR filters of a symmetric structure.
In order to apply FIR filters, a flexible fi lter architecture has been designed and implemented as an RTL hardware model with VHDL. Digital fi ltering can be broken down to a sum of additions and multiplications. Since embedded multipliers are limited in FPGAs the designed architecture is based on a resizeable parallel and sequential part which allows it to make the best use of the multipliers taken the desired clock frequency into account. The architecture supports symmetric FIR f ilters of an odd order number. The order can vary from 7 to 575 in prede fined steps. A suitable FPGA is necessary to implement filters of high orders.
This architecture has been used to implement a set of single and dual carrier systems based on filters of order 383 on a Spartan 3 FPGA.
In order to test the system, the architecture has been surrounded by an environment consisting of a set of interfaces enabling the system to receive incoming data from an ADC and send filtered data to a pc for further analysis. Through this, the filter architecture was verifi ed and the implemented filters tested successfully. | | Type | Master's thesis [Academic thesis] | | Year | 2012 | | Publisher | Technical University of Denmark, DTU Informatics, E-mail: reception@imm.dtu.dk | | Address | Asmussens Alle, Building 305, DK-2800 Kgs. Lyngby, Denmark | | Series | IMM-M.Sc.-2012-102 | | Note | DTU supervisor: Alberto Nannarelli, an@imm.dtu.dk, DTU Informatics | | Electronic version(s) | [pdf] | | Publication link | http://www.imm.dtu.dk/English.aspx | | BibTeX data | [bibtex] | | IMM Group(s) | Computer Science & Engineering |
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