Digital signal processing

In 1979, Intel introduced the first microprocessor with an architecture and instruction set specifically tailored to digital signal processing (DSP) applications. Since then, general purpose DSP chips have been launched by Texas Instruments, IBM, Analog Devices, Motorola, Inmos and Lucent (AT&T) among others, and DSP ASIC (application specific circuits) cores are available from these manufacturers and many others, in particular the OAK DSP core.

The rapid growth in the exploitation of DSP in digital communications is not surprising considering the commercial advantages now offered by their low cost and ease of programmability.

Modern DSP devices, for example the TMS 320C6X series, are extremely powerful, able to implement the modem, error correction, channel equalization and voice coding functions required in a modern digital cellular phone within a single device, and potentially several times over. Some of the basic benchmarks for the processor are shown in the table below.

DSP performance characteristics

As an example, this processor can implement a raised cosine filter with 50 coefficients (taps), which would typically be used in a M-ary QAM data modem, within approximately 0.15ms and could thus accommodate a data symbol rate of about 3000000 symbols per second.