Multi-hop wireless communication system

A two-dimensional multi-hop wireless communication system comprising:

• multiple node devices, each node device of the multiple node devices including multiple input multiple output (MIMO) antennas, such that each of the node devices is capable of performing a relay function via the MIMO antennas, so as to form the two-dimensional multi-hop wireless communication system from wireless links between the node devices,
• wherein the two-dimensional multi-hop wireless communication system applies a multiple input multiple output (MIMO) scheme to a transmission/reception scheme of network coding, so as to create a bi-directional wireless relay transmission that multiplexes a forward link and a backward link in all of the wireless links formed by the node devices,
• wherein each of the node devices performs transmission/reception processing and a relay transmission of data, and
• wherein a multi-hop relay of a two-dimension bi-directional flow with a single channel is created by applying the network coding to the multiple node devices.

A multi-hop wireless communication system comprising:

• multiple node devices, each node device of the multiple node devices including multiple input multiple output (MIMO) antennas, such that each of the node devices is capable of performing a relay function via the MIMO antennas, so as to form the multi-hop wireless communication system from forward links and backward links between the node devices,
• wherein the multi-hop wireless communication system applies a multiple input multiple output (MIMO) scheme to a transmission/reception scheme of network coding,
• wherein the multi-hop wireless communication system applies a space time block coding (STBC) scheme,
• wherein each of the node devices comprises:
• a STBC reception data generating unit configured to perform a STBC reception data generating process to generate STBC reception data from received wireless signals wirelessly received via the MIMO antennas;
• a STBC channel matrix generating unit configured to perform a STBC channel matrix generating process to generate a STBC equivalent channel matrix from channel information estimated from training signals wirelessly received via the MIMO antennas;
• a MIMO detecting unit configured to perform a MIMO detecting process to estimate estimation symbols from the generated STBC equivalent channel matrix and the generated STBC reception data;
• a network decoding unit configured to perform a network decoding process to generate relay signals, which are two consecutive symbols to the forward link and the backward link, from the estimated estimation symbols;
• a relay control unit configured to perform a destination control process;
• a network coding unit configured to perform a network coding process of two consecutive transmitting symbols to generate two consecutive transmitting signals from the generated relay signals;
• a STBC transmission data generating unit configured to perform a STBC transmission data generating process to generate STBC transmission data from the transmitting signals generated by the network coding unit;
• and
• a training signal adding unit configured to add the training signals to the generated STBC transmission data and to perform a training signal adding process,
• wherein the STBC transmission data, to which the training signals are added is transmitted as transmitted wireless signals,
• wherein the relay control unit performs the destination control process that determines that either the generated relay signals are signals for a local node device or that the generated relay signals are signals for another node device,
• wherein, in a case where the relay control unit determines that the generated relay signals are signals for the local node device, the processing of the node device is finished,
• wherein, in a case where the relay control unit determines that the relay signals are signals for the another node device, in order to perform a network decoding process at a next time slot, the relay control unit stores the generated relay signals as the transmitted data of a previous time slot,
• wherein the MIMO detecting process uses a ZF algorithm or a MMSE algorithm in MIMO reception,
• wherein, with respect to the node devices of the multi-hop wireless communication system, in a case where a (k−1)-th node and a (k+1)-th node are transmitting nodes, two consecutive transmitting signals s1k−1,s2k−1 of the (k−1)-th node are modeled respectively by using the following two expressions,
• s1k−1=sF1k−1+sB1k−1 mod q
• s2k−1=sF2k−1+sB2k−1 mod q, and
• wherein, two consecutive transmitting signals s1k+1,s2k+1 of the (k+1)-th node are modeled respectively by using the following two expressions,
• s1k+1=sF1k+1+sB1k+1 mod q
• s2k+1=sF2k+1+sB2k+1 mod q,
• where sF1k−1,sF2k−1 are two consecutive transmitting symbols for the forward link of the (k−1)-th node, sB1k−1,sB2k−1 are two consecutive transmitting symbols for the backward link of the (k−1)-th node, sF1k+1,sF2k+1 are two consecutive transmitting symbols for the forward link of the (k+1)-th node, sB1k+1,sB2k+1 are two consecutive transmitting symbols (transmitting signal) for the backward link of the (k+1)-th node, and q is a lattice size of lattice coding.

A two-dimensional multi-hop wireless communication system comprising:

• multiple node devices, each node device of the multiple node devices including multiple input multiple output (MIMO) antennas, such that each of the node devices is capable of performing a relay function via the MIMO antennas, so as to form the two-dimensional multi-hop wireless communication system from forward links and backward links between the node devices,
• wherein each of the node devices of the two-dimensional multi-hop wireless communication system comprises:
• a MIMO detecting unit configured to perform a MIMO detecting process to estimate estimation symbols from channel information estimated from training signals wirelessly received via the MIMO antennas and received wireless signals wirelessly received via the MIMO antennas;
• a network decoding unit configured to perform a network decoding process to generate relay signals from the estimated estimation symbols;
• a relay control unit configured to perform a destination control process;
• a network coding unit configured to perform a network coding process to generate transmitting signals from the generated relay signals;
• and
• a training signal adding unit configured to add the training signals to the transmitting signals generated by the network coding unit and to perform a training signal adding process,
• wherein the transmitting signals to which the training signals are added are transmitted as transmitted wireless signals, and
• wherein a multi-hop relay of a two-dimension bi-directional flow with a single channel is created by applying the network coding to the multiple node devices.