Ofdm apparatus and method

A method for generating a DCT and DST of a vector comprising:

• partitioning the vector into a plurality of sub-vectors;
• generating at least one input spatial light pattern responsive to each sub-vector;
• generating for each input spatial light pattern an output spatial light pattern that is an interference pattern produced by light from the input spatial light pattern;
• sensing the output spatial light pattern at discrete spatial points and generating signals responsive to the sensed light;
• and
• processing the signals to generate the DCT and DST of the vector.

An OFDM modem for decoding an OFDM symbol and recovering a data symbol vector encoded therein comprising:

• a signal processor that receives a first vector representing the OFDM symbol and generates a second and a third vector therefrom, wherein the second vector has components, each of which is proportional to a sum of two different components of the first vector, and the third vector has components, each of which is proportional to a difference between two different components of the first vector;
• and
• an optical processor that receives the second and third vectors and optically processes the received vectors to generate signals responsive to a DCT and a DST of the second vector and signals responsive to a DCT and DST of the third vector;
• wherein
• the signal processor receives the signals generated by the optical processor and processes them to decode the OFDM symbol and recover the data symbol vector encoded therein.