I do not completely understand your bit pattern, but it seems as though the basic time interval is 40 us. Perhaps you could create a mapping process: a zero produces one 40 us element, a one produces two 40 us elements, and the separator is a high 40 us element. Then convert your 16-bit pattern to a bit array, feed the array through a for loop and create the pulse output pattern by the mapping process above. You could feed this to a digital output for simulating your transducer.
Lynn