How to do adaptive delta modulation in labview

Short-range digital voice transmission is used extensively in modern consumer electronics.
Products such as cordless telephones, wireless headsets (for mobile and landline telephones), baby monitors are to name just a few of the items that use digital techniques to wirelessly communicate voice information. Wireless environments are inherently noisy, so the voice coding scheme chosen for such an application must be robust in the presence of bit errors.

Pulse Coded Modulation (PCM) and its derivatives are commonly used in wireless consumer products for their compromise between voice quality and implementation cost, but these schemes are not robust in the presence of bit errors.

Adaptive Delta Modulation (ADM) is another voice coding scheme; a mature technique that should be considered for these applications because of its bit error robustness and its low implementation cost.

ADM quantizes the difference between the current sample and the predicted value of the next sample.
ADM uses a variable 'step height' to adjust the predicted value of the next sample so that both slowly and rapidly changing input signals can be faithfully reproduced.
One bit (i.e. "1" or "0") is used to represent each sample in ADM[1].
The one-bit-per-sample ADM data stream requires no data framing, thereby minimizing the workload on the host microcontroller.

Bit errors are present in any digital wireless application. Most voice coding techniques provide good audio quality in an ideal operating environment, but the challenge is to generate good audio quality in an everyday environment, where there is the presence of bit errors.

Traditional performance metrics (e.g. SNR) do not accurately measure perceived audio quality for various voice coding methods and input signals. "Mean Opinion Score" (MOS) testing overcomes the limitations of other metrics by successfully quantifying perceived audio quality.
The MOS testing uses a scale of 1 to 5 to represent audio quality, with 1 representing very bad speech quality and 5 representing excellent speech quality. A MOS score of 4 or higher represents 'toll quality' speech, which is equivalent to that audio quality obtained during a traditional telephone call [2].