Summary
Automatic recognition systems are commonly used in speech processing to classify observed utterances by the speaker's identity, dialect, and language. These problems often require high processing throughput, especially in applications involving multiple concurrent incoming speech streams, such as in datacenter-level processing. Recent advances in processor technology allow multiple processors to reside within the same chip, allowing high performance per watt. Currently the Cell Broadband Engine has the leading performance-per-watt specifications in its class. Each Cell processor consists of a PowerPC Processing Element (PPE) working together with eight Synergistic Processing Elements (SPE). The SPEs have 256KB of memory (local store), which is used for storing both program and data. This paper addresses the implementation of language, dialect, and speaker recognition on the Cell architecture. Classically, the problem of performing speech-domain recognition has been approached as embarrassingly parallel, with each utterance being processed in parallel to the others. As we will discuss, efficient processing on the Cell requires a different approach, whereby computation and data for each utterance are subdivided to be handled by separate processors. We present a computational model for automatic recognition on the Cell processor that takes advantage of its architecture, while mitigating its limitations. Using the proposed design, we predict a system able to concurrently score over 220 real-time speech streams on a single Cell.