1. It is suggested that full diversity gain can be achieved over a Rayleigh faded MISO channel by simply transmitting the same symbol at each of the transmit antennas simultaneously. Is this correct?
2. An L × 1 MISO channel can be converted into a time diversity channel with L diversity branches by simply transmitting over one antenna at a time.
1. In this way, any code designed for a time diversity channel with L diversity branches can be used for a MISO (multiple input single output) channel with L transmit antennas. If the code achieves k-fold diversity in the time diversity channel, how much diversity can it obtain in the MISO channel? What is the relationship between the minimum product distance metric of the code when viewed as a time diversity code and its minimum determinant metric when viewed as a transmit diversity code?
2. Using this transformation, the rotation code can be used as a transmit diversity scheme. Compare the performance of this code and the Alamouti scheme in a 2 × 1 Rayleigh fading channel, using BPSK symbols. Which one is better? How about using QPSK symbols?