Digital Signal Processing (DSP)

Advances in Analogue to Digital Converters allied with increased capabilities of CMOS LSI devices have enabled Digital Signal Processing design (DSP design) to become a cost effective option for many new applications. Functions previously achievable only by using analogue design techniques can now be implemented using DSP algorithms, with all the inherent advantages of repeatable accuracy and quantified precision. DSP design opens a world of opportunity for the development of facilities that would be difficult, if not impossible, to achieve with traditional analogue techniques.

At Plextek, DSP is an approach to solving a problem rather than the process of using standard DSP devices. Such products are used when appropriate, but so are specific implementations in hardware, software or firmware. Each problem requires individual consideration, depending on computational intensity, power efficiency, size, cost and development time constraints.

DSP is normally one element of a larger system and the first task in most projects is to undertake a system design to determine the optimum partitioning of the problem. Plextek uses the latest industry standard tools such as MATLAB, Simulink and MATHCAD to enable rapid system simulation. Tools are available to port these simulation models directly to target hardware although, in most cases, a degree of customisation is required.

Another key element in DSP design is an appreciation of the core algorithms required for common functions. Most DSP problems involve time domain and frequency domain transforms and an understanding of how these transforms are implemented is vital during the system design phase. Bit precision is another aspect that is important for low power operation. Plextek has developed a portfolio of IP blocks that can be reused for specific applications. Plextek has experience developing DSP solutions for:

• Communications Systems - Mobile and fixed communications for standards based and proprietary systems. Implementation ranges from microcontroller though single and multiple DSP devices to FPGA and full custom ASIC
• Test and Measurement equipment - For communications test sets, manufacturing test and general purpose test equipment
• Video - Basic image processing and compression/decompression
• Audio - Voice encoding/decoding and echo control
• Location Systems - Range and direction systems (Radar & Sonar) for high-end defence and low-end consumer applications