The last major update to the ITU-T Basic Operators [6] was in 2005, with a follow on update in 2009. These basic operators serve as a foundation for reference software of codecs specified by 3GPP. During the last several years, processors with wide accumulators, and support for single-instruction-multiple-data (SIMD), and very long instruction word (VLIW) features have become prevalent. The basic operators of 2009 now need to be extended to leverage these capabilities of modern processors so that implementations with lower mega-cycles-per-second (MCPS) and lower-power may be realized.
Enhanced Voice Services (EVS) is one of the recent codecs defined by 3GPP that can leverage these features of modern processors. The existing EVS reference software would have to be appropriately modified to leverage these extended basic operators without changing the underlying algorithm. This is referred to as an alternative EVS implementation using the extended basic operators.
This alternative EVS implementation would have to be evaluated to ensure that inter-operability is maintained in addition to ensuring that voice quality is not impacted.
The present document covers the following topics:
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Assessment of the gaps between modern processors and the existing set of basic operators (STL2009) [6].
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Proposal of an extended set of operators addressing modern DSP architectures as an extension to STL2009.
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Assessment of merits of an alternative EVS implementation using extended STL2009 Basic Operators.
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Proposal for validation of an alternative EVS implementation using extended STL2009 Basic Operators.