January 3, 2010    

Matched filtering

Matched filtering is an important signal processing function. The 
transducer sends out unique transmit sequences, each of which can be 
recognized by a matched filter. The key advantage is that the transmit 
sequence can be expanded in time at a lower amplitude and transmitted 
at a lower peak pressure amplitude level. This can reduce bioeffects 
and contrast agent effects. It can also preserve axial resolution with 
depth, and increased sensitivity and tissue penetration depth. 

A variety of Matched filtering have been implemented. There are two 
classical types of transmit waveforms, a coded binary sequence and a 
chirped pulse, which are borrowed from radar.