1-18. (canceled)
19. A receiving apparatus that demodulates a modulated signal received via a plurality of antennas, the receiving apparatus comprising:
a transmission-channel estimating unit that estimates a transmission-channel response matrix in accordance with a quantity of antennas and a quantity of symbols based on a received signal vector, the received signal vector being a vector expression of a plurality of baseband digital signals obtained by performing certain receiving processing;
a hard-decision sequence estimating unit that estimates a hard decision sequence based on the received signal vector and the transmission-channel response matrix, and outputs a hard decision sequence obtained as an estimation result and first likelihood information corresponding to the hard decision sequence; and
a soft-decision value creating unit that creates second likelihood information corresponding to a sequence that a specific bit in the hard decision sequence is inversed by using the received signal vector, a transmission-channel response matrix reconstructed by reducing a dimension of the transmission-channel response matrix, and the hard decision sequence, and creates a soft decision value of each bit in the hard decision sequence based on the second likelihood information and the first likelihood information.
20. The receiving apparatus according to claim 19, wherein the soft-decision value creating unit includes:
a vector subtraction unit that creates a replica of a symbol containing a subject bit as a target for soft decision value creation, based on the transmission-channel response matrix and a symbol having an inverse bit of a specific bit in the hard decision sequence, and subtracts the replica from the received signal vector;
a weight creating unit that reconstructs the transmission-channel response matrix by reducing a dimension, and creates a weight matrix based on reconstructed transmission-channel response matrix;
a weight multiplication unit that multiplies subtraction result obtained by the vector subtraction unit by the weight matrix;
a signal determination unit that estimates a sequence that a bit in the hard decision sequence is inversed, from a multiplication result obtained by the weight multiplication unit based on transmission signal mapping;
a likelihood creating unit that creates the second likelihood information based on the received signal vector, the transmission-channel response matrix, and a determination result obtained by the signal determination unit; and
a soft-decision value calculating unit that calculates a soft decision value based on the first likelihood information and the second likelihood information.
21. The receiving apparatus according to claim 20, wherein the likelihood creating unit creates a replica by multiplying the transmission-channel response matrix by the determination result obtained by the signal determination unit, and creates the second likelihood information based on the replica and the received signal vector.
22. The receiving apparatus according to claim 20, wherein
the transmission-channel estimating unit further estimates information about noise power applied on the received signal vector, and
the soft-decision value creating unit further uses the information about the noise power in creation of the soft decision value.
23. The receiving apparatus according to claim 22, wherein the weight creating unit creates a weight matrix based on the reconstructed transmission-channel response matrix and the information about the noise power.
24. The receiving apparatus according to claim 20, wherein
the soft-decision value creating unit further includes a replica creating unit that creates a replica of the hard decision sequence based on the transmission-channel response matrix,
the vector subtraction unit, the weight multiplication unit, the signal determination unit, and the likelihood creating unit perform a series of processing on replica created by the replica creating unit, and create third likelihood information,
the soft-decision value calculating unit selects one of the second likelihood information and the third likelihood information, and creates a soft decision value based on selected likelihood information and the first likelihood information.
25. The receiving apparatus according to claim 20, wherein
the hard-decision sequence estimating unit stores therein, in addition to performing a process of outputting the hard decision sequence and the first likelihood information corresponding to the hard decision sequence, likelihood information corresponding to a transmission symbol candidate calculated in the process of the processing, and
when stored likelihood information corresponding to a transmission symbol candidate having an inverse bit of a specific bit in the hard decision sequence is present, the likelihood creating unit further outputs the stored likelihood information as the second likelihood information.
26. The receiving apparatus according to claim 20, further comprising a signal decoding unit that decodes a soft decision value received from the soft-decision value creating unit repeatedly a certain number of times, wherein
the signal decoding unit creates a certain advance information to be used for repeated decoding, and outputs the advance information to the hard-decision sequence estimating unit and the soft-decision value creating unit,
the hard-decision sequence estimating unit refers also to the advance information, and performs estimation processing of the hard decision sequence, and creation processing of the first likelihood information corresponding to the hard decision sequence, and
the soft-decision value creating unit refers also to the advance information, and performs processing that can be performed by the likelihood creating unit and processing that can be performed by the soft-decision value calculating unit.
27. A receiving apparatus configured to be used in a system that employs one of OFDM (Orthogonal Frequency Division Multiplexing) and MC-CDMA (Multi Carrier-Code Division Multiple Access), and to demodulate a multi-carrier modulated signal received via a plurality of antennas, the receiving apparatus comprising:
a signal converting unit that converts a time-domain signal as an input signal per antenna into a frequency-domain signal;
the transmission-channel estimating unit, the hard-decision sequence estimating unit, and the soft-decision value creating unit, that performs soft-decision value creation processing according to claim 19, by using sub-carrier signal obtained by the signal converting unit; and
a rearranging unit that rearranges a soft decision value per sub-carrier created by the soft-decision value creating unit to a serial form.
28. The receiving apparatus according to claim 19, wherein
the soft-decision value creating unit includes:
a vector subtraction unit that creates a replica of a symbol containing a subject bit as a target for soft decision value creation, based on the transmission-channel response matrix and a symbol having an inverse bit of a specific bit in the hard decision sequence, and subtracts the replica from the received signal vector;
a weight creating unit that reconstructs the transmission-channel response matrix by reducing a dimension, stores therein reconstructed transmission-channel response matrix, creates a weight matrix based on the reconstructed transmission-channel response matrix, and outputs a specific row vector included in the weight matrix as a weight;
a weight multiplication unit that multiplies a subtraction result obtained by the vector subtraction unit by the weight;
a signal determination unit that determines a multiplication result obtained by the weight multiplication unit based on transmission signal mapping, and estimates a sequence that a bit in the hard decision sequence is inversed based on a determination result;
a likelihood creating unit that creates the second likelihood information based on the received signal vector, the transmission-channel response matrix, and the determination result obtained by the signal determination unit; and
a soft-decision value calculating unit that calculates a soft decision value based on the first likelihood information and the second likelihood information,
wherein
when the vector subtraction unit receives an output from the signal determination unit, the vector subtraction unit creates a replica by using the signal determination output instead of the symbol having an inverse bit of a specific bit in the hard decision sequence, and subtracts the replica from a previous vector subtraction result,
when the weight creating unit stores therein a transmission-channel response matrix reconstructed by reducing a dimension, the weight creating unit creates a weight matrix based on stored reconstructed transmission-channel response matrix instead of the transmission-channel response matrix, and
the vector subtraction unit, the weight creating unit, the weight multiplication unit, and the signal determination unit perform a series of processing on all bits in the hard decision sequence, and estimate a sequence that a bit in the hard decision sequence is inversed.
29. The receiving apparatus according to claim 28, wherein the weight creating unit outputs a smallest row vector as a weight, the smallest row vector being smallest among row vectors included in the weight matrix.
30. The receiving apparatus according to claim 28, wherein the likelihood creating unit creates a replica by multiplying the transmission-channel response matrix by the determination result obtained by the signal determination unit, and creates the second likelihood information based on the replica and the received signal vector.
31. The receiving apparatus according to claim 28, wherein
the transmission-channel estimating unit further estimates information about noise power applied on the received signal vector, and
the soft-decision value creating unit further uses the information about the noise power in creation of the soft decision value.
32. The receiving apparatus according to claim 31, wherein the weight creating unit creates a weight matrix based on the reconstructed transmission-channel response matrix and the information about the noise power.
33. The receiving apparatus according to claim 28, wherein
the soft-decision value creating unit further includes a replica creating unit that creates a replica of the hard decision sequence based on the transmission-channel response matrix,
the vector subtraction unit, the weight multiplication unit, the signal determination unit, and the likelihood creating unit perform a series of processing on replica created by the replica creating unit, and create third likelihood information,
the soft-decision value calculating unit selects one of the second likelihood information and the third likelihood information, and creates a soft decision value based on selected likelihood information and the first likelihood information.
34. The receiving apparatus according to claim 28, wherein
the hard-decision sequence estimating unit stores therein, in addition to performing a process of outputting the hard decision sequence and the first likelihood information corresponding to the hard decision sequence, likelihood information corresponding to a transmission symbol candidate calculated in the process of the processing, and
when stored likelihood information corresponding to a transmission symbol candidate having an inverse bit of a specific bit in the hard decision sequence is present, the likelihood creating unit further outputs the stored likelihood information as the second likelihood information.
35. The receiving apparatus according to claim 28, further comprising a signal decoding unit that decodes a soft decision value received from the soft-decision value creating unit repeatedly a certain number of times, wherein
the signal decoding unit creates a certain advance information to be used for repeated decoding, and outputs the advance information to the hard-decision sequence estimating unit and the soft-decision value creating unit,
the hard-decision sequence estimating unit refers also to the advance information, and performs estimation processing of the hard decision sequence, and creation processing of the first likelihood information corresponding to the hard decision sequence, and
the soft-decision value creating unit refers also to the advance information, and performs processing that can be performed by the likelihood creating unit and processing that can be performed by the soft-decision value calculating unit.
36. A receiving apparatus configured to be used in a system that employs one of OFDM (Orthogonal Frequency Division Multiplexing) and MC-CDMA (Multi Carrier-Code Division Multiple Access), and to demodulate a multi-carrier modulated signal received via a plurality of antennas, the receiving apparatus comprising:
a signal converting unit that converts a time-domain signal as an input signal per antenna into a frequency-domain signal;
the transmission-channel estimating unit, the hard-decision sequence estimating unit, and the soft-decision value creating unit, that performs soft-decision value creation processing according to claim 28, by using sub-carrier signal obtained by the signal converting unit; and
a rearranging unit that rearranges a soft decision value per sub-carrier created by the soft-decision value creating unit to a serial form.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for forwarding a message, wherein the method is applied to a layer-2 network device and comprises:
receiving a message from a source end;
judging a type of the message; and
when the type is judged to be a specified type, forwarding the message according to a processing flow corresponding to the specified type.
2. The method according to claim 1, wherein judging the type of the message comprises:
judging whether the message is of one of the following specified types: multicast data message, multicast protocol message and non-multicast message.
3. The method according to claim 2, wherein forwarding the message according to the processing flow corresponding to the specified type comprises:
when the specified type is the multicast data message, acquiring indicating information of the multicast data message, the indicating information corresponding to a destination forwarding port of the multicast data message;
acquiring the destination forwarding port according to the indicating information; and
forwarding the multicast data message to the destination forwarding port.
4. The method according to claim 2, wherein the indicating information comprises the following information in the multicast data message: source Internet Protocol (IP) address, destination IP address and Virtual Local Area Network (VLAN) field value.
5. The method according to claim 3, wherein before the destination forwarding port is acquired according to the indicating information, the method comprises:
discarding or flooding the multicast data message when the destination forwarding port indicated by the indicating information is not acquired.
6. The method according to claim 2, wherein forwarding the message according to the processing flow corresponding to the specified type comprises:
when the specified type is the multicast protocol message, classifying the multicast protocol message; and
forwarding the multicast protocol message according to the type to which the multicast protocol message belongs.
7. The method according to claim 2, wherein forwarding the multicast protocol message according to the processing flow corresponding to the specified type comprises:
when the specified type is the non-multicast message, forwarding the non-multicast data message by using the Media Access Control (MAC) address in the non-multicast data message.
8. A device for forwarding a message, wherein the device is applied to a layer-2 network device and comprises:
a receiving component configured to receive a message from a source end;
a judgment component configured to judge the type of the message; and
a forwarding component configured to forward the message according to a processing flow corresponding to a specified type when the judgment component determines that the type is the specified type.
9. The device according to claim 8, wherein the judgment component is configured to judge whether the message is of one of the following specified types:
multicast data message, multicast protocol message and non-multicast message.
10. The device according to claim 9, wherein the forwarding component comprises:
a first acquisition element configured to acquire the indicating information of the multicast data message when the specified type is the multicast data message, the indicating information corresponding to a destination forwarding port of the multicast data message;
a second acquisition element configured to acquire the destination forwarding port according to the indicating information; and
a first forwarding element configured to forward the multicast data message to the destination forwarding port.
11. The device according to claim 9, wherein the forwarding component comprises:
a classifying element configured to classify the multicast protocol message when the specified type is the multicast protocol message; and
a second forwarding element configured to forward the multicast protocol message according to a type to which the multicast protocol message belongs.
12. The device according to claim 9, wherein the forwarding component comprises:
a third forwarding element configured to, when the specified type is the non-multicast message, forward the non-multicast data message by using the MAC address in the non-multicast data message.