Coherent cooperative transmission from multiple adjacent antennas to a distant stationary antenna through AWGN channels

The information transmission from a cluster of adjacent antennas to a distant stationary antenna through additive white Gaussian noise channels is considered. With the coherent cooperative transmission approach, information bits are first shared among this cluster of transmit antennas, and then these antennas adjust their carrier phases, carrier frequencies, and symbol timings, so that signals containing the same data arrive at the receive antenna coherently and thus combine constructively in the transmission medium. To achieve this, first, a common time scale must be tracked by all transmit antennas. This time scale is distributed in a master-slave style, with the clock of the receive antenna acting as the master clock. Secondly, due to the different propagation delays both from the master to the slaves, and from the transmit antenna to the receive antennas, pre-compensation is employed at transmit antennas. We derive a mathematical model for this transmission scheme. The probability density functions of variables in this model are determined, and the bit error rates are computed, for various data energy distributions and headers.