US Patent 7551943 Wireless communication method, wireless communication system, and wireless communication device

A wireless communication method includes: transmitting an estimation signal from a first communication device with a first plurality of antenna elements to a second communication device with a second plurality of antenna elements at a training phase for synchronization in a first type of wireless communication using an adaptive array system between the first and second communication devices; detecting the estimation signal by the second communication device; and estimating, based on the detection of the estimation signal, whether or not a wireless communication channel between the first and second communication devices is adaptable to a second type of wireless communication using a multi-input multi-output (MIMO) system.