CELLONICS
The Modulation
and Demodulation Technology
-Blog By Ashwini Nasre (Final Year Student, ETC, ACET, Nagpur)
Idea: Are you tired of slow
modem connections? Cellonics Incorporated has developed new technology that may
end this and other communications problems forever. The new modulation and
demodulation technology is called Cellonics.
In digital communication, CellonicsTM
offers a fundamental change to the way modem solutions have traditionally been
designed and built. It introduces a simple and
swift-Rate decoding solution to the receiving and decoding of a
modulated signal.
Outline: The
technology names as CELLONICS as it was invented by the scientists from CWC
(Center of Wireless Communication) and Computational Science Department in
Singapore.
For the
last 60 years, the way radio receivers are designed and built has undergoes
amazingly little changes. Much of the current approach circuit could be
attributed to EH Armstrong, the oft-credited Father of FM, who invented the super heterodyne method
in 1918. He further developed it into the completely FM commercial system in
1933 for use in public-radio broadcasting. Today, more than 98% of receivers in
radios, television and mobile phones use this method.
In general, this technology will allow for
modem speeds that are 1,000 times faster than our present modems. The
development is based on the way biological cells communicate with each other
and nonlinear dynamical systems (NDS). Major Telco’s, which are
telecommunications companies, will benefit from the incredible speed,
simplicity, and robustness of this new technology, as well as individual users.
In current technology, the ASCII uses a combination of ones and zeros to
display a single letter of the alphabet (Cellonics, 2001). Then the data is
sent over radio frequency cycle to its destination where it is then decoded.
The original technology also utilizes carrier signals as a reference which uses
hundreds of wave cycles before a decoder can decide on the bit value (Legard,
2001), whether the bit is a one or a zero, in order to translate that into a
single character. The Cellonics technology came about after studying biological
cell behaviour. The study showed that human cells respond to stimuli and
generate waveforms that consist of a continuous line of pulses separated by
periods of silence.
The Cellonics technology found a way to mimic
these pulse signals and apply them to the communications industry (Legard,
2001). The Cellonics element accepts slow analog waveforms as input and in
return produces predictable, fast pulse output, thus encoding digital
information and sending it over communication channels. Nonlinear Dynamical
Systems (NDS) are the mathematical formulations required to simulate the cell
responses and were used in building Cellonics. Because the technique is
nonlinear, performance can exceed the norm, but at the same time,
implementation is straightforward (Legard, 2001). This technology will be most
beneficial to businesses that do most of their work by remote and with the use
of portable devices. The Cellonics technology will provide these devices with
faster, better data for longer periods of time (Advantages, 2001). Cellonics
also utilizes a few discrete components, most of which are bypassed or consume
very little power. This reduces the number of off the shelf components in
portable devices while dramatically decreasing the power used, leading to a
lower cost for the entire device. The non-portable devices of companies will
benefit from the lack of components the machines have and the company will not
have to worry so much about parts breaking.
IDEOLOGIES OF THE TECHNOLOGY
The Cellonics technology is
revolutionary and unconventional approach based on the nonlinear dynamical
systems and modeled after biological cell behavior. When used in the field of
communication, the technology has the ability to encode, transmit and decode
the digital information powerfully over a variety of physical channels, be they
cables or wirelessly through air.
It encodes and decodes signals at one cycle
per symbol- a feature not found elsewhere. It simplicity will absolute the
super heterodyne receiver design that has been in use since its invention by
Major Edward Armstrong in 1918. In fact, according to one estimate, 98% of the
world’s radio systems are still based on this super heterodyne design.
Cellonics incorporated has invented and patented a number of circuits that
mimic about the above biological cell behavior. Cellonics technology circuits
are incredibly simple with the advantages of low-cost, low power consumption
and smallness of size. When applied in communication, Cellonics technology is a
fundamental modulation and demodulation technique. These receivers are used as
devices that generate the pulses from the received analog signal and perform
demodulation based on pulse counting.
The subsystem used in super heterodyne
design consists of RF (radio-frequency) amplifiers, mixers, filters, oscillators,
phase locked loops and other components which are all complex, noisy and power
hungry. Capturing a communications element from air to retrieve its modulated
signal is not easy and a system often needs to spend thousands of carrier
cycles to recover just one bit information. This process of demodulation is
inefficient and newly emerging schemes results in complex chips difficult and
expensive to manufacture. So it was necessary to invent the new demodulation circuit,
which does the job of conventional super heterodyne receiver but after a far
lesser component count, faster and lower in power consumption, and processing
greater signal robustness. These requirements were met by designing a circuit
which models the biological cell behavior.
SIMPLE CELLONIC CIRCUIT
Cellonics incorporated
has developed the number of patented families of simple cellonics circuits that
are useful for various applications. One of these cellonics circuits is
extremely simple circuit that exhibits the ‘S curve’ transfer characteristics.
The circuit also contains the negative impedance converter.
The transfer characteristics consist of
three different regions. The two lines at the top and the bottom have positive
slope i.e. 1/RF and they represent the region in which the OP-AMP is operated
in saturated (nonlinear) mode. The middle segment has the negative slope (negative
resistance) which represents that the OP-AMP is operated linearly. It is the
negative resistance region which allows the OP-AMP to oscillate and produce
pulses which are bounded by the negative and positive saturating voltages.
For
the ease of explanation, consider the transfer characteristics as shown as
above. Let us assumed the input voltage to be a triangular input voltage
waveform. Here we have dVs/dt the negative slope, the number of pulses to be
assumed at the output =V0 (depending on the slope of triangular input
waveform). Whenever the slope is positive, the OP-AMP is stable and the outputs
are the constant saturation voltages. Thus the silent period is observed i.e.
no spike is present. On the other hand, with properly selected circuit
parameter whenever the slope of input triangular waveform is negative, the
OP-AMP is unstable. In this region, the output is oscillating in nature.
The duration of each pulse is similar and
the number of pulses generated depends on the length of time that the slope
remains negative. Thus by controlling the duration of negative slope, the
number of pulses to be produced at the output of OP-AMP can be controlled. The
Cellonics circuits are robust against noise perturbations- as long as the
effective negative slope keeps the OP-AMP circuit unstable, the noise will not
have the effect on the pulse generation. The level of tolerance against the
noise perturbations is carried out by proper selection of circuit parameters in
the design.
INFERENCE
The Cellonics communication method is
one inspired by how biological cell signal. It is a fresh and novel look at how
digital signals may be conveyed. In this digital day and age, it is timely;
current digital communication designs are mostly derived from old analog signal
methods. With the cellonics method, much of the sub-systems, in a traditional
communication system are not required. Noise generating and power consuming
systems such as voltage controlled oscillators, PLLs, mixers; power amplifiers,
etc. are eliminated. To a communications engineer, this is unheard off. One
just doesn’t build a communication device without an oscillator, mixer, etc.
Such is the revolutionary impact of
Cellonics. Engineers will have to reform their thinking that such a simple
solution is possible.
