A novel algorithm for online inexact string matching and its FPGA implementation
Accelerating inexact string matching procedures is of utmost importance when dealing with practical applications, where huge amount of data must be processed in real time, as usual in bioinformatics or cybersecurity. Inexact matching procedures can yield multiple shadow hits, which must be filtered according to some criterion, to obtain a concise and meaningful list of occurrences. The filtering procedures are often computationally demanding and are performed offline in a post-processing phase. This paper introduces a novel algorithm for Online Approximate String Matching (OASM) able to filter shadow hits on the fly, according to general purpose heuristic rules that greedily assign priorities to overlapping hits. An FPGA hardware implementation of OASM is proposed and compared with a serial software version, showing that even on entry level FPGAs the procedure can reach a high degree of parallelism, with a low usage of logic elements. This makes the proposed architecture very competitive in terms of both performances and cost of the overall computing system.
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