Method and apparatus for modulating signals

An apparatus for transmitting a signal, comprising:

• a data generator adapted to provide digital data;
• and
• a signal modulator adapted to receive the digital data, wherein the signal modulator includes:
• a digital signal processor adapted to receive digital data at a receive sampling rate and define a code word based on a subset of the digital data;
• an address buffer coupled to the digital signal processor and adapted to receive the code word and store a base address;
• a counter adapted to increment an address offset at a transmit sampling rate, the transmit sampling, rate being a multiple of the receive sampling rate;
• and
• a first memory device having a plurality of memory locations and adapted to receive the base address and the address offset and provide a first waveform data sample from the memory location addressed by the base address and the address offset.

An apparatus, comprising:

• means for receiving digital data at a receive sampling rate;
• means for determining a code word based on a subset of the digital data, the code word defining an address;
• means for generating an address offset based on a transmit sampling rate;
• and
• means for outputting a first waveform data sample based on the address and the address offset.

A method for modulating a signal, comprising:

• receiving digital data at a receive sampling rate, the time interval between digital data samples defining a bit interval;
• determining a code word based on a subset of the digital data;
• initializing a counter at the start of the bit interval;
• incrementing the counter at a transmit sampling rate;
• determining an address based on the code word and an address offset stored in the counter;
• accessing a first memory device containing waveform data based on the address;
• and
• outputting a first waveform data sample from the first memory device.