Quantized Run Length Encoding QRLE -New Compression Method-: Application to ECG Transmission via IEEE802.11b WLAN Channel

A new method of signal compression, called Quantized Run Length Encoding QRLE, based upon the `classical' run length method combined to discrete wavelet transform thresholding planned for a transmission via the WiFi IEEE 802.11b WLAN channel, simulated by Simulink/Matlab Integrated Development Environment IDE, is presented in this work. The key idea of our new method consists of quantifying each pair of zero followed by its corresponding run number, issued from the RLE, by one value consisting on the run number value plus an offset of predetermined integer value. In this work, the suitable offset was adjusted to 1024(≡2
<sup>10</sup>
). This leads to quantizing the `new' run number on 11 bits while the non null ECG thresholded ECG signal samples are quantized on 10 bits. The trivial advantage of this method is suppression, and consequently gaining, of all zeros. We have applied the proposed algorithm to extracted ECG signals, from the universal MIT-BIH arrhythmia data base. To evaluate the performance of the new QRLE compression method, we have simulated transmitting the compressed ECG signal via the Simulink/Maltab IEEE 802.11b WLAN noisy channel model. Besides the perceptible visual inspection, three criteria are used, in our evaluation phase, that are: compression ratio -CR-, the normalized root mean squared error (NRMSE), and the difference between the original and reconstructed versions of the ECG signal. The obtained results are around 10:1 in terms of CR, 0.07 in terms of NRMSE and a difference of about (10
^-4
) ± 0.02. Moreover, a comparative study with respect to selected ECG compression algorithms show the higher performance of the developed new technique called `Quantized run length encoding QRLE'.