System and method for providing 3-dimensional joint interleaver and circulation transmissions
AssigneeISSC Technologies Corp.
InventorsJeng-Hong Chen, Pansop Kim
Life of this patent
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Abstract
System performance in wireless communication is improved by increasing diversity in time, space and frequency. Information to be transmitted is processed by a convolution encoder to produce encoded bits. The encoded bits are interleaved and mapped to subcarriers. Symbols are created from the subcarriers and the symbols are transmitted so as to increase diversity in time, space and frequency. Circulation transmission in addition to interleaving is used to increase diversity. For example, circulation transmission can be symbol based or subcarrier based.
Claims14
A three-Dimensional (3D) interleaver for interleaving an input stream in an Orthogonal-Frequency-Division-Multiplexing (OFDM) based Multiple-Input-Multiple-Output (MIMO) system, the 3D interleaver configured to:
- receive an input bit stream A(k), k=0, 1, 2, . . . , NCBPS×NI−1, where NCBPS is the number of input bits per OFDM symbol, NI is the number of OFDM symbols per 3D interleaver;
- select two parameters Nrow and Ncolumn, where Nrow×Ncolumn=NCBPS;
- form a 3D structure, the 3D structure having NI×Nrow×Ncolumn empty cells, dimensions of the 3D structure being NI, Nrow and Ncolumn respectively;
- write each input bit A(k) to each cell of the 3D structure, position of each cell in the 3D structure being defined by three co-ordinates, x, y, and z, where 0≦x≦Ncolumn−1, 0≦y≦NI−1, and 0≦z≦Nrow−1;
- interleave the input bit stream A(k), k=0, 1, 2, . . . , NCBPS×NI−1 into NI groups of cells in a 3D structure, each group being associated with one OFDM symbol, wherein consecutive input bits are assigned to different groups of cells to allow for the two consecutive input bits to be transmitted in different OFDM symbols;
- and
- output an interleaved bit stream B(j), j=0, 1, 2, . . . , NCBPS×NI−1, from the 3D structure.
A method for interleaving a plurality of input data bits in an Orthogonal-Frequency-Division-Multiplexing (OFDM) based Multiple-input-multiple-output (MIMO) system, the method comprising:
- receiving an input bit stream;
- writing the received input bit stream to a 3D structure;
- selecting three parameters NI, Nrow and Ncolumn, where Nrow×Ncolumn=NCBPS, NCBPS is the number of input bits per OFDM symbol, NI is the number of OFDM symbols per 3D interleaver;
- interleaving the input bit stream to generate a corresponding interleaved bit stream;
- and
- outputting the interleaved bit stream from the 3D structure, wherein two consecutive input bits of the input bit stream are transmitted in different OFDM symbols simultaneously.
Dependencies are inferred from the claim text.