Acoustic Modem - Modulator - COS LUT

[Iyury1]

Summary

The cosine look-up table should values from -1 to 1 representing all of the possible values of the cosine function. The resolution or precision of the values is set by the number of values in the table.

Checklist

• Find COS LUT examples
• Select size of look-up table (number of entries) - can be arbitrary for now
• Choose data type for table entries. They could be of type "signed", "std_logic_vector", or "sfixed" (from the fixed_pkg library).

Since we are writing the table entries to a DAC which requires a positive binary number to represent a voltage, we will choose a voltage level to represent the value of "0", then all other table entries should be above or below this value. This means that is is possible for all entries in the table to be positive.