Further analysis and development of the polyphase filterbank inversion algorithm of PST

To achieve the temporal resolution required for high-precision pulsar timing, it is necessary to invert the over-sampled polyphase filter bank (PFB) outputs that will be generated by the beam formers of both Mid.CBF and Low.CBF.  The PFB inversion algorithm has been described and demonstrated in theory, but no implementation has ever been demonstrated in the field.  It is the most novel and risky component of the PST signal chain.  Therefore, it is necessary to thoroughly test and optimise the implementation that will be deployed for PST, which is part of the current prototype software (dspsr).

All of the stories required to complete this feature have been completed. The key outcomes are:

• A Matlab model that can generate PFB output signals (test data) for inversion using dspsr
• A well-defined set of tests that demonstrate correctness of both the Matlab model and the PFB inversion algorithm implemented by dspsr.