Method and device for detection of data transmitted by spectrum spreading
AssigneeCommissariat a l'Energie Atomique
InventorsDominique Noguet, Mathieu Bouvier des Noes
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Abstract
The invention relates to a method and device for the joint detection of data transmitted by direct sequence spread spectrum (DSSS). The device comprises means of using a Cholesky decomposition to calculate a matrix U such that: L=UH×U, where L is an equalization matrix and U is an upper triangular matrix. The means for using a Cholesky decomposition comprise MAC cells (MAC1, MAC2, . . . , MACN) and a diagonal cell (DIAG) of a systolic network. The MAC cells and the diagonal cell are also used to calculate an estimated vector {circumflex over (d)} of received data. For example, the invention applies to the field of digital mobile phone transmissions.
Claims20
An apparatus for calculating coefficients of a Cholesky decomposition of a matrix, the apparatus comprising:
- a multiplicity, N, of multiplication accumulation (MAC) cells to be connected together in series, wherein each MAC cell includes an accumulation input, an accumulation output, a return input, a return output, and a coefficient input, wherein the accumulation output of a previous (pth) MAC cell is to be connected to the accumulation input of a next ((p+1)st) MAC cell (p=1, . . ., N-1);
- and
- a diagonal cell to be connected to the multiplicity of MAC cells, wherein the diagonal cell includes an accumulation input, a result output, a return input, a return output, and a coefficient input, wherein the accumulation input of the diagonal cell is to be connected to the accumulation output of the Nth MAC cell,
- wherein coefficients of the Cholesky decomposition are to be coupled to return and coefficient inputs of at least one of said MAC cells and to the coefficient input of the diagonal cell.
A system for jointly receiving multiple communication signals, the system comprising:
- means for receiving said communication signals;
- and
- a circuit coupled to said means for receiving and to jointly estimate data carried on said communication signals, the circuit comprising:
- a multiplicity, N, of multiplication accumulation (MAC) cells to be connected together in series, wherein each MAC cell includes an accumulation input, an accumulation output, a return input, a return output, and a coefficient input, wherein the accumulation output of a previous (pth) MAC cell is to be connected to the accumulation input of a next ((p+1)st) MAC cell (p=1, . . ., N−1);
- and
- a diagonal cell to be connected to the multiplicity of MAC cells, wherein the diagonal cell includes an accumulation input, a result output, a return input, a return output, and a coefficient input, wherein the accumulation input of the diagonal cell is to be connected to the accumulation output of the Nth MAC cell,
- wherein coefficients of a Cholesky decomposition of a matrix to be used to jointly estimate said data are to be coupled to return and coefficient inputs of at least one of said MAC cells and to the coefficient input of the diagonal cell.
An apparatus for calculating coefficients of a Cholesky decomposition of a matrix, the apparatus comprising:
- a number, N, of first modules to be connected together in series, each of said first modules configured to perform multiplication and accumulation operations;
- and
- a second module to be connected to the first modules, with an accumulation output of the Nth first module to be connected as an input to the second module,
- wherein the second module is structurally different from the first modules,
- wherein coefficients of the Cholesky decomposition are to be coupled to at least one input of at least one first module and to an input of the second module,
- wherein said second module is to provide, as an output, a coefficient of the Cholesky decomposition.
A system for jointly receiving multiple communication signals, the system comprising:
- means for receiving said communication signals;
- and
- a circuit coupled to said means for receiving and to jointly estimate data carried on said communication signals, the circuit comprising:
- a number, N, of first modules to be connected together in series, each of said first modules configured to perform multiplication and accumulation operations;
- and
- a second module to be connected to the first modules, with an accumulation output of the Nth first module to be connected as an input to the second module, wherein the second module is structurally different from said first modules,
- wherein coefficients of a Cholesky decomposition of a matrix are to be coupled to at least one input of at least one first module and to an input of the second module, and
- wherein said second module is to provide, as an output, a coefficient of the Cholesky decomposition.
Dependencies are inferred from the claim text.