This paper presents a novel adaptive signal quality evaluation method for Signal Waveform Modulation Multi-Level (SWM-ML) disc. The experimental results show the adaptive signal quality evaluation method is useful and proper for SWM ML disc.
This paper presents the improved readout system of multi-level signal waveform modulation read-only disk. The
experimental results show the performance of the improved readout system is better than that of the former system.
The Radio Frequency (RF) signal of the Multi-Level Run-Length-Limited (ML-RLL) read-only disc is different from
that of DVD, so the readout system of the ML-RLL read-only disc is built specially. The readout system of the ML-RLL
read-only disc can realize servo control, RF signal readout and so on. The readout system consists of Digital Versatile
Disc (DVD) traverse, analog front-end and digital processing part. Analog front-end can realize front-end amplification
of the output signal of the optical pick-up and power drive of mechanism. Digital processing part mainly consists of
digital circuits, which functions are the servo controlling, demodulation and decoding of RF signal, general control and
so on. The whole system is implemented on two Field Programmable Gate Array (FPGA) chips and the experimental
results show a good performance. We tested the important signals, and experimental results are also given to verify the
performance of this development platform, which meets the controlling and detecting requirements to multi-level
read-only disc completely. The Bit Error Rate (SER) can achieve below 10-4.
Multi-level run-length limited (ML-RLL) recording technology can increase the capacity of the read-only disc without changing the optical and mechanical units. The characteristic of the push-pull signal of the multi-level run-length limited read-only disc is analyzed and compared with that of the conventional DVD read-only disc. Experimental results show the effect of the variation of pit depth is more than other parameters and the peak-to-peak amplitude of the push-pull signal in the ML-RLL read-only disc is about 2.9 times of that in the DVD read-only disc while the variance is nearly 3.2 times. The push-pull method in the ML-RLL read-only disc is more sensitive than that in the conventional DVD read-only disc.