Method for 2D antenna rake combining in a code division multiplication access system

A direct sequence spread spectrum signal receiver, comprising:

• a. a pilot spreading sequence generator;
• b. a data spreading sequence generator;
• c. a first antenna;
• d. a first plurality of RAKE fingers, the first plurality of RAKE fingers coupled to the first antenna, the pilot spreading sequence generator, and the data spreading sequence generator, the first plurality of RAKE fingers further adapted to despread a signal component and to generate estimated pilot signals and estimated data symbols;
• e. a second antenna;
• f. a second plurality of RAKE fingers, the second plurality of RAKE fingers coupled to the second antenna, the pilot spreading sequence generator, and the data spreading sequence generator, the second plurality of RAKE fingers further adapted to despread a signal component and to generate estimated pilot signals and estimated data symbols;
• g. a coefficient generator coupled to the first plurality of RAKE fingers and to the second plurality of RAKE fingers, the coefficient generator adapted to receive the estimated pilot signals from the first plurality of RAKE fingers and from the second plurality of RAKE fingers, the coefficient generator further adapted to determine, in one step, a set of combining coefficients using a Minimum Mean Square Error combining method that considers space and time variables of the estimated pilot symbols;
• h. a first plurality of multipliers, each multiplier of the first plurality of multipliers coupled to a corresponding RAKE finger from the first plurality of RAKE fingers and adapted to receive estimated data symbols from the corresponding RAKE finger, each multiplier further coupled to the coefficient generator and adapted to receive combining coefficients, each multiplier further adapted to produce an output that is a product of the estimated data symbols and the combining coefficients;
• and
• i. a second plurality of multipliers, each multiplier of the second plurality of multipliers coupled to a corresponding RAKE finger from the second plurality of RAKE fingers and adapted to receive estimated data symbols from the corresponding RAKE finger, each multiplier further coupled to the coefficient generator and adapted to receive combining coefficients, each multiplier further adapted to produce an output that is a product of the estimated data symbols and the combining coefficients;
• and
• j. an adder, coupled to the first plurality of multipliers and to the second plurality of multipliers, the adder adapted to receive the output of the first plurality of multipliers and to receive the output of the second plurality of multipliers.

A method for combining a direct sequence spread spectrum signal comprising data signal and pilot signal components that each may be characterized with a space variable and a time variable, comprising:

• a. despreading a received signal into said data signal and pilot signal components;
• b. forming an autocorrelation matrix from an expectation value of the product of said signal components and the hermetian adjoint of said signal components;
• and
• c. determining in one step a set of combining coefficients from said autocorrelation matrix using a Minimum Mean Square Error combining method that considers said space and time variables of the signal components in parallel;
• and
• d. Multiplying each said data signal component with a corresponding said combining coefficient derived from step c.