METHOD OF DATA TRANSMISSION IN A MULTI-CARRIER BASED TRANSMISSION SYSTEM AND DEVICE IMPLEMENTING THE METHOD

• US 20080187005A1
• Filed: 02/04/2008
• Published: 08/07/2008
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Brunel, Loic, CHAUVIERE, Benoit, Bouttier, Arnaud
• Granted Patent: US 8,249,043 B2
• Time in Patent Office: Days
• US Class Current: 370/480
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

The invention concerns multi-carrier based digital telecommunication systems where the channel is used to transport several data streams according to the frequency division multiple access scheme.

The proposed method concerns a mapping of data on physical resource in a transmission system where data of elementary streams is distributed over several physical resource blocks, and within each resource block in order to get data from a plurality of elementary streams on at least one sub-carrier and at least a symbol time of each physical resource block. This allows to achieve a good diversity of the allocation of the different streams, leading to the advantage, among others, that poor transmission conditions affecting a particular sub-carrier or a particular time duration, will not concentrate its effects on a particular stream.

Claims

1. Method of data transmission in a multi-carrier based transmission system, the transmission being made over a channel shared among a number of data streams according to a frequency division multiple access scheme, data from different sources or to different destinations being sent by streams of symbols, the physical resource blocks being defined as blocks constituted by a given number of consecutive sub-carriers and a transmission time of a given number of symbol durations, some of these streams beind transmited in a distributed mode, comprising the following steps:

a distributed allocation step of some other distributed streams onto at least one distributed physical resource block in a second distributed mode;

characterized in that the distributed allocation step comprises;

a spreading step of the symbols of the distributed streams onto and within the distributed physical resource blocks in a way where each sub-carrier and each symbol time of the distributed physical resource blocks will be allocated with symbols from at least two different streams.

2. Method according to claim 1 characterized in that the spreading step comprises:

a multiplexing step of symbols from a first plurality of L data blocks (6.3), fed with symbols from the distributed streams, to a second plurality of L data blocks (6.5) to be allocated to physical resource blocks.

3. Method according to claim 2 characterized in that, each data block of the first and second plurality being of size S and being indexed from 0 to S-1, each plurality being indexed from 0 to L-1, each symbol of rank i of the data block of rank j of the first plurality is multiplexed to the symbol of rank k=i of the data block of rank 1=(i+j) mod L of the second plurality.

4. Method according to claim 2 characterized in that, each data block of the first and second plurality being of size S and being indexed from 0 to S-1, each plurality being indexed from 0 to L-1, L being a sub-multiple of S, each symbol of rank i of the data block of rank j of the first plurality is multiplexed to the symbol of rank k=(i+j) mod L+[i/L]*L of the data block of rank 1=i mod L of the second plurality.

5. Method according to claim 2 characterized in that, each data block of the first and second plurality being of size S and being indexed from 0 to S-1, each plurality being indexed from 0 to L-1, L being a sub-multiple of S, each symbol of rank i of the data block of rank j of the first plurality is multiplexed to the symbol of rank k=(i+j) mod S of the data block of rank 1=i mod L of the second plurality.

6. Method according to claim 2 characterized in that, each data block of the first and second plurality being of size S and being indexed from 0 to S-1, each plurality being indexed from 0 to L-1, L being a sub-multiple of S, s being chosen between 1 and L inclusive, each symbol of rank i of the data block of rank j of the first plurality is multiplexed to the symbol of rank k=i of the data block of rank 1=(i+j+s) mod L of the second plurality.

7. Method according to claim 6 characterized in that, said transmission system being cellular, the s parameter is dependent of the cell in which the method is used.

8. Method according to any of claims 2 to 7 characterized in that it further comprises:

a final allocation step of the symbols of the second plurality of data blocks to the physical resource blocks.

9. Method according to claim 8 characterized in that, the size S of the data blocks being chosen equal to the size of the physical resource blocks, each symbol of each data block of the second plurality is allocated to the symbol of same rank in a corresponding physical resource block.

10. Method according to claim 9 characterized in that, some symbols in the physical resource blocks being forbidden, the symbols allocated to these forbidden symbols are punctured.

11. Method according to claim 8, characterized in that, some symbols in the physical resource block being forbidden, S being chosen equal to the number of available symbols in the resource blocks, each symbol of each data block of the second plurality is allocated to the symbol of same rank in the subset constituted by the available symbols of a corresponding physical resource block (9.21, 9.22, 9.23).

12. Method according to claim 8, characterized in that, some symbols in the physical resource block being forbidden, S being chosen greater to the number of available symbols in the resource blocks and lower or equal to the total number of symbols of the resource blocks, each symbol of each data block of the second plurality is allocated to the symbol of same rank in a corresponding physical resource block, symbols allocated to forbidden symbols being punctured.

13. Method according to claim 8, characterized in that, some symbols in the physical resource blocks being forbidden, the number and/or the position of the forbidden symbols being variable within the physical resource blocks, S being chosen greater to the minimum number of available symbols in the resource blocks and lower or equal to the total number of symbols of the resource blocks, each symbol of each data block of the second plurality is allocated uniformly to the symbol of same rank in a corresponding physical resource block, the rank being defined uniformly on a subset of symbols of the physical resource blocks, symbols allocated to forbidden symbols being punctured (9.11, 9.12, 9.13).

14. Method according to claim 8, characterized in that, some symbols in the physical resource blocks being forbidden, the number and/or the position of the forbidden symbols being variable within the physical resource blocks, S being chosen greater to the minimum number of available symbols in the resource blocks and lower or equal to the total number of symbols of the resource blocks, each symbol of each data block of the second plurality is allocated uniformly to the symbol of same rank in a corresponding physical resource block, the rank being defined uniformly on a subset of symbols of the physical resource blocks, symbols allocated to forbidden symbols being allocated to non allocated available symbols (9.31, 9.32, 9.33).

15. Method according to any of claims 2 to 14, characterized in that it further comprises:

a first allocation step of symbols from the different streams in the first plurality of data blocks.

16. Method according to claim 1, characterized in that symbols from the different streams are directly allocated into the physical resource blocks at the exact place defined by any of claims 2 to 15.

18. Data transmission device (13.1) according to claim 15, characterized in that the spreading means are adapted to implement the method according to one of the claims 2 to 14.

17. Data transmission device (13.1) in a multi-carrier based transmission system, the transmission being made over a channel shared among a number of data streams according to a frequency division multiple access scheme, data from different sources or to different destinations being sent by streams of symbols, the physical resource blocks being defined as blocks constituted by a given number of consecutive sub-carriers and a transmission time of a given number of symbol durations, some of these streams beind transmited in a distributed mode, comprising the following means:

distributed allocation means to allocate some other distributed streams onto at least one distributed physical ressource block in a second distributed mode;

characterized in that the distributed allocation means comprises;

spreading means to spread the symbols of the distributed streams onto and within the distributed physical ressource blocks in a way where each sub-carrier and each symbol time of the distributed physical ressource blocks will be allocated with symbols from at least two different streams.