Software implementation of matrix inversion in a wireless communication system

A process for performing singular value decomposition of a matrix of channel values in a wireless communication device, the process comprising:

• providing a processor that includes a vector unit, the vector unit including multiple instances of a CORDIC functional unit as execution stages of a processor pipeline, each CORDIC functional unit configured to perform one iteration of a CORDIC algorithm;
• and
• the vector unit reading and writing to first and second registers included in the processor;
• wherein, the matrix inversion of the matrix of channel values is performed by a coordinate rotation digital computer instruction set using the vector unit and the first and second registers, and the instruction set includes instructions that read the first and second registers, perform a coordinate rotation digital computer process and write results of the process to the first and second registers, wherein the process includes:
• calling a first instruction of the instruction set that reads x and y coordinate values from the first register, reads angle z and iteration count n values from the second register, performs M iterations of the CORDIC algorithm using the multiple instances of the CORDIC functional unit, and writes updated and x and y values from the M iterations to the first register without writing updated z and n values from the M iterations to the second register;
• calling a second instruction of the instruction set that reads x and y coordinate values from the first register, reads angle z and iteration count n values from the second register, performs M iterations of the CORDIC algorithm using the multiple instances of the CORDIC functional unit, and writes updated z and n values to the second register without writing updated x and y values to the first register.

A digital signal processor in a wireless communication device, the processor comprising:

• means for vector processing comprising a vector unit including multiple instances of a CORDIC functional unit as execution stages of a processing pipeline, each CORDIC functional unit configured to perform one iteration of a CORDIC algorithm;
• first and second storage means coupled to and accessible by the means for vector processing;
• and
• means for singular value decomposition of a matrix of channel values, the means for singular value decomposition comprising an instruction set including:
• a first instruction for reading x and y coordinate values from the first storage means, reading angle z and iteration count n values from the second storage means, performing M iterations of the CORDIC algorithm using the multiple instances of the CORDIC functional unit, and writing updated x and y values from the M iterations to the first storage means without writing updated z and n values from the M iterations to the second storage means;
• and
• a second instruction for reading x and y coordinate values from the first storage means, reading angle z and iteration count n values from the second storage means, performing M iterations of the CORDIC algorithm using the multiple instances of the CORDIC functional unit, and writing updated z and n values to the second storage means without writing updated x and y values to the first storage means.