Block spreading for orthogonal frequency divsion multiple access systems
AssigneeCommonwealth Scientific and Industial Research Organisation
InventorsXiaojing Huang, Yingjie Jay Guo
Life of this patent
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Abstract
A method of block spreading data, the method comprising the steps of: (a) providing a first input data sequence; (b) forming a periodic extension of the input data sequence to form an extended input data sequence; (c) multiplying the extended input data sequence by a complex number spreading sequence to produce a spread signal sequence; and (d) outputting the spread signal sequence.
Claims10
A method of block spreading input data sequences, the method comprising the steps of:
- (a) providing a first input data sequence;
- (b) forming a periodic extension of the input data sequence to form an extended input data sequence;
- (c) multiplying the extended input data sequence by a complex number spreading sequence to produce a spread signal sequence;
- and
- (d) outputting the spread signal sequence.
A transmitter system for transmitting an input data sequence, the transmitter including:
- a first data grouping unit dividing the input data sequence into a series of groups;
- a block spreading unit for block spreading each of the members of the group series, multiplying the members of the group with a complex exponential sequence to form a corresponding block spread series of groups;
- an adder for adding together corresponding members of each group to form a transmission group;
- a transmitter for transmitting the transmission group.
A receiver system for receiving a complex exponential block spread data sequence, the receiver system including:
- an input data symbol tokeniser receiving the complex exponential block spread data sequence;
- a series of block despreading units, each of the units interconnected to the tokeniser, each of said block despreading units multiplying a grouped version of the input data signals with a complex conjugate exponential to produce a series of substantially orthogonal transmitted data sequences;
- a series of phase rotation units for undertaking a predetermined phase rotation of each orthogonal transmitted data sequence to produce a corresponding rotated orthogonal transmitted data sequence;
- a regrouping unit connected to the phase rotation unit for reordering each of the rotated orthogonal transmitted data sequences to produce an output data sequence.
Dependencies are inferred from the claim text.