A 7th order FIR filter
operating in duty-cycle scenario (switching VLPR and VLPS modes in a predefined interval) was implemented as a testing algorithm.
To show the filtering effect, we processed the gradient data provided by EGG_NOM2 from ESA over the short time interval between 0:0:1.6 on October 17th, 2010 and 23:59:59.6 on October 26th, 2010, using a band-pass FIR filter
. The pass band frequency is 0.005~0.1 Hz.
The HT is implemented as a FIR filter
of order 60 using the Parks-McClellan algorithm.
The channel model simulates AWGN with a simple static multipath environment using some parameters such as frequency offset; timing offset using epsilon, taps of FIR filter
to add delay to multipath and a random number generator seed for the noise source .
The digital delay filter in Figure 2 is an FIR filter
. If the order of the filter is N, the coefficient vector can be expressed as
A demonstration of the FIR filter
structure is provided in Figure 1.
While laser scanner can be considered as a standalone positioning technology, the hybrid filter uses a PF as the core main filter, integrated and enhanced by another robust FIR filter
, based on the proposed scheme by .
In , the FIR filter
for a linear homogeneous system is proposed.
This is achieved using a moving average filter, which is a simple implementation of an FIR filter
. This filter has a linear phase so as not to distort the waveforms and a low roll-off rate.
As IIR filtering being a nonlinear method , our technique of using linear phase sharp transition FIR filter
is less complex and does not involve many iterations as the filter response is specified precisely over the entire band.
The input- output relation of a FIR filter
is given by,