Horner form arbitrary coefficient multiplierless fir filter

A coefficient multiplier circuit for a filter, the coefficient multiplier circuit comprising:

• a partial product stage configured to provide a plurality of integer partial products of an input data vector;
• and
• a multiplexing stage comprising:
• one or more multiplexers configured to receive the plurality of integer partial products of the input data vector, and addressed using one or more bits of an input coefficient vector;
• and
• an output connected with the one or more multiplexers, and with one or more summers of the filter.

A system comprising:

• a refrigeration system configured to maintain a refrigerated environment;
• a plurality of qubits disposed in the refrigerated environment;
• and
• control circuitry connected to the plurality of qubits, the control circuitry comprising, for each qubit of the plurality of qubits, a respective waveform synthesizer configured to drive the qubit, wherein the respective waveform synthesizer comprises an interpolation filter circuit comprising:
• a series-connected arrangement of unit delays and summers in an alternating pattern;
• and
• a plurality of coefficient multipliers, each having a respective output connected with one or more of the summers, and each comprising a multiplexing stage comprising one or more multiplexers addressed using one or more bits of a respective input coefficient vector,
• wherein a first coefficient multiplier of the plurality of coefficient multipliers comprises a partial product stage configured to provide a plurality of integer partial products of an input data vector to the multiplexing stages of the plurality of coefficient multipliers.