Cooperative communication method and system

A system for cooperative communication, comprising:

• a plurality of transmission devices, each comprising a signal transceiver and a processor;
• and
• a plurality of receiving devices corresponding to the plurality of transmission devices, and each comprising a signal transceiver and a processor,
• wherein in a first phase, the processor of at least one of the plurality of transmission devices is configured to perform a first phase precoding on data using a multicasting precoding matrix, and the signal transceiver of the at least one of the plurality of transmission devices is configured to transmit the data precoded by the first phase precoding to transmission devices other than the at least one of the plurality of transmission devices;
• and in a second phase, the processors of the plurality of transmission devices are configured to perform a second phase precoding on data received in the first phase using a joint precoding matrix, and the signal transceivers of the plurality of transmission devices are configured to transmit the data precoded by the second phase precoding to the plurality of receiving devices corresponding to the plurality of transmission devices, and wherein the transmission devices use respective multicasting precoding matrixes and respective joint precoding matrixes, and wherein the processors of the plurality of transmission devices are configured to calculate the multicasting precoding matrix and the joint precoding matrix based on an estimated transmission rate or an estimated transmission power of the plurality of transmission devices in the first phase and the second phase.