Two Dimensional Eye Diagram for QAM/CAP 16 Constellation
showing the output of the equalizer during convergence with high SNR
FIR, IIR, Kalman Filter
These filter types are the basic building blocks of
all DSP systems. There are many ways of implementing all these filters
which gives us the ability to configure the implementation for speed,
and or area.
Adaptive Filters: LMS, CMA
Most DSP Systems are adaptive. The Error Criteria
of adaptation decides what the filter is called. LMS and CMA are used
mostly for their low hardware cost implementation and ease of analysis.
LMS Adaptive Equalizer can be implemented with Pipeline in
Update. The forward calculation block consists of Booth Multipliers merged with Multi-Input Adder.
The Multi-Input Adder is a Wallace Tree Adder with 4-2 Compressor.
For Performance reasons Custom 4-2 Compressor Cells are implemented at
Circuit Level and Characterized by HSpice.
Trellis Coded Modulation
Coders & Viterbi Decoders.
To combat noise and ISI distortions of channels,
TCM coding and Viterbi decoders are used. These advanced techniques
give us the ability utilize the near optimal capacity of the channel
predicted by Shannon's Theorem.
Fully Digital Clock Recovery
Timing Detector using 2x Oversampled ADC.
ADC clock is non-synchronous to Transmit Clock.
Data Recovery done using Digital Interpolation.
Initial Filter Development In Matlab language.
Data-Path Optimization of Kalman Filter in Verilog RTL.
Polynomial Based Farrow Interpolator
Polynomial Coefficients Optimized with AMPL Script
Reed-Solomon Forward Error
Correction Coding/Decoding implementations
Forward Error Correction is another way to increase
the reliability of channels.
Coordinate transformation Algorithm using CORDIC
Sine/Cosine in Verilog
Area Optimized CORDIC unit for Sine/Cosine Calculation
for Complex Value Magnitude Calculation
Verilog and VHDL RTL Design
Most of our Designs are Implemented In HDLs. We
selectively implement performance or power sensitive blocks using
Full-Custom CMOS Design Methodology to meet Area/Power/Speed requirements.