A circuit performs complex division and dual complex multiplication. The circuit has a plurality of multipliers. Each of the plurality of multipliers is used in both the complex division and the dual complex multiplications. The circuit also has a plurality of components capable of adding and subtracting. Each adding and subtracting component is used during the complex division and the dual complex multiplication and switches between operation as an adder and a subtractor between performing the complex division and the dual complex multiplication. Preferred potential uses for the circuit are in a receiver of a user equipment or a base station. The circuit is used in a fast Fourier transform (FFT) based channel estimation or a FFT based data detection.

A system (400) alternatively performs real matrix operation in a first mode or performs complex matrix multiplication in a second mode. One input matrix (e.g., {B}) stays in a plurality of memory fields (430-k), while the other input matrix (e.g., {A}) is loaded into a plurality of registers (410-k). Parallel operating groups (405-k, 409-(k+1)) combine elements of {A} with elements of {B}. The groups (405-k, 409-(k+1)) comprise the memory fields (430-k), the registers (410-k) as well as computational units (440-k), switches (420-k) and adder units (460-k). The adder units (460-k) are configured by the switches (420-k) to operate as adders or to operate as accumulators, depending on the mode. Adders provide intermediate results and accumulators accumulate these intermediate results (e.g., Sum) to elements of the resulting matrix {C}. For complex multiplication, real (Re) and imaginary (Im) parts of matrix elements are in processed in adjacent groups. The system (400) uses logarithmic representations of the matrix elements and further comprises a log converter (490) and a plurality of inverse log converters (450-k).

A digital signal processor architecture particularly adapted for performing fast Fourier Transform algorithms efficiently. The architecture comprises dual, parallel multiply and accumulate units in which the output of the multiplier circuit portion of each MAC is cross-coupled to an input of the adder unit of the other MAC as well as to an input of the adder unit of the same MAC to which the multiplier belongs.

A circuit is capable of performing a complex division and dual complex multiplication. The complex division involves dividing a first complex value by a second complex value and the dual complex multiplication involves multiplying a third complex value by a fourth complex value and a fifth complex value by a sixth complex value. The circuit comprises a first input configured to receive the first and second complex values when the circuit is performing the complex division and the third and fourth complex values when the circuit is performing the dual complex multiplication. A second input is configured to receive the second complex value when performing the complex division and the fifth and sixth complex values when performing dual complex multiplication. A first output produces a result of complex multiplication of the third and fourth complex values when the circuit is performing the dual complex multiplication. A second output produces a result of the complex division of the first complex value divided by the second complex value when the circuit is performing the complex division and complex multiplication of the fifth complex value by the sixth complex value when performing the dual complex multiplication.

A method and apparatus for multiplying two digital pairings representing complex numbers is described. The method includes preloading a memory with contents based on the second complex combination and the basis vector, and repeatedly addressing the memory based on the first complex combination taken L bits at a time in order to accumulate a complex product combination. The complex multiplication apparatus is preferably constructed as high speed circuitry on a gallium arsenide integrated circuit chip.