Processing Technology
Digital Signal Processing

Digital Signal Processors (DSPs) are processors or microcomputers whose hardware, software, and instruction sets are optimized for high-speed numeric processing applications.  An essential requirement for processing digital data representing analog signals in real time. The combination of design elements, arithmetic operators, memory handling, instruction set, parallelism, data addressing that provide this ability forms the key difference between DSPs and other kinds of processors. Understanding the relationship between real-time signals and DSP calculation speed provides some background on just how special this combination is. The real-time signal comes to the DSP as a train of individual samples from an analog-to-digital converter (ADC). To do filtering in real-time, the DSP must complete all the calculations and operations required for processing each sample (usually updating a process involving many previous samples) before the next sample arrives. To perform high-order filtering of real-world signals having significant frequency content calls for really fast processors.

Intelitec Pacific have been designing DSP based hardware solutions for over seven years.

Voice Compression
ITU-T G.723.1

G.723.1 is a speech compression algorithm standardized by the International Telecommunications Union. The ITU G.723.1 standard specifies a coded representation that can be used for compressing the speech or other audio signal component of multimedia services at a very low bit rate as part of the overall H.324 family of standards. This coder was optimized to represent high quality speech at low rates using a limited amount of complexity.

It encodes speech or other audio signals in frames using linear predictive analysis-by-synthesis coding. G.723.1 has dual coding rates at 5.3 and 6.3 kbps. The excitation signal for the high rate coder is Multipulse Maximum Likelihood Quantization (MP-MLQ) and for the low rate coder is Algebraic-Code-Excited Linear-Prediction (ACELP).   The G.723.1 vocoder delivers the highest compression ratio of any of the current ITU standards without compromising speech quality.

The subjective speech quality produced by the 6.3 kbps version of G.723.1 is essentially equivalent to 32 kbps G.726 adaptive differential pulse code modulation (ADPCM) and 16 kbps G.728 Low-Delay Code Excited Linear Prediction (LD-CELP). Thus it is a “toll” quality speech coder.

In 1997, Intelitec Pacific  became one of the first engineering firms in the world to demonstrate practical DSP based designs using the then newly standardized algorithm.

Battery Technology
Lithium Polymer

Since the early research stages of Li-Polymer in the mid-1990's, the technology has been of specific interest to manufacturers. It allows for the possibility to design even smaller and lighter devices than were previously possible.

The Li-Polymer battery cell doesn't employ the hard metal casing as does conventional nickel-metal hydride or lithium-ion batteries. Instead, the electrodes are covered with a flexible plastic or aluminum laminate foil. The battery contains no liquid as do traditional batteries, but instead the electrolyte is polymerized into a gel-like form. This allows for batteries to be designed in a variety of sizes and shapes that would be impossible using conventional battery cells.

Whilst the chemistry allows for lighter weight and wafer thin configurations, the batteries are still expensive to manufacture and are yet to pack the energy densities found in today's Li-ion.  However, watch this space, until we see room-temperature dry Lithium Polymer cells in about 2005, manufacturers will be combining the best of Li-ion and Li-polymer in hybrid cells to achieve the best of both worlds.