US 8,711,920 B1Granted

System and method for multi-threaded OFDM channel equalizer

AssigneeRedline Communications Inc.

InventorOctavian Valeriu Sarca

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Abstract

A system for an orthogonal frequency division multiplexed (OFDM) equalizer, said system comprising a program memory, a program sequencer and a processing unit connected to each other, wherein the processing unit comprises an input selection unit, an arithmetic logic unit (ALU) and an output selection unit; further wherein the program sequencer schedules the processing of one or more symbol-carrier pairs input to said OFDM equalizer using multiple threads; retrieves, for each of the one or more symbol-carrier pairs, multiple program instructions from said program memory; generates multiple expanded instructions corresponding to said retrieved multiple program instructions; and further wherein said ALU performs said processing of the one or more symbol-carrier pairs using the multiple threads across multiple pipeline stages, wherein said processing comprises said ALU executing one or more arithmetic operations to process said expanded instructions using said multiple threads across the multiple pipeline stages.

Claims30

Dependent claims

A system for an orthogonal frequency division multiplexed (OFDM) equalizer, said OFDM equalizer comprising one or more inputs and one or more outputs, said system comprising a program memory, a program sequencer and a processing unit connected to each other, wherein:

the processing unit comprises
an input selection unit,
an arithmetic logic unit (ALU) having one or more inputs and an output,
wherein said ALU is pipelined and has a plurality of pipeline stages, and an output selection unit;
further wherein the program sequencer
schedules the processing of one or more symbol-carrier pairs input to said OFDM equalizer using a plurality of threads,
retrieves, for each of the one or more symbol-carrier pairs, a plurality of program instructions from said program memory, and
generates a plurality of expanded instructions corresponding to said retrieved plurality of program instructions;
and
further wherein
said ALU performs said processing of the one or more symbol-carrier pairs using the plurality of threads across said plurality of pipeline stages,
wherein said processing comprises said ALU executing one or more arithmetic operations to process said expanded instructions using said plurality of threads across said plurality of pipeline stages, said arithmetic operations comprising
addition of two or more complex numbers,
multiplication of two or more complex numbers,
sign change of a complex number,
complex conjugation of a complex number,
scaling of a complex number, and
division of one by the square root of a real number,
further wherein said ALU executes said division of one by the square root of a real number using a lookup table.

16 more elements

A method of processing one or more symbol-carrier pairs in an OFDM equalizer, said OFDM equalizer comprising a program memory, a program sequencer and a processing unit connected to each other, wherein the processing unit comprises an input selection unit, an arithmetic logic unit (ALU) having one or more inputs and one output, wherein said ALU is pipelined and has a plurality of pipeline stages, and an output selection unit, said method comprising:

scheduling the processing of one or more symbol-carrier pairs using a plurality of threads;
retrieving, for each of the one or more symbol-carrier pairs, a plurality of program instructions from said program memory;
generating a plurality of expanded instructions corresponding to said retrieved plurality of program instructions;
and
processing the one or more symbol-carrier pairs using the plurality of threads across said plurality of pipeline stages, said processing comprising
executing one or more arithmetic operations to process said expanded instructions using said plurality of threads across said plurality of pipeline stages, said arithmetic operations comprising
adding two or more complex numbers,
multiplying two or more complex numbers,
changing the sign of a complex number,
complex conjugating of a complex number,
scaling of a complex number, and
dividing one by the square root of a real number, said dividing performed using a lookup table.

9 more elements

Dependencies are inferred from the claim text.