| In this thesis, we study the performance of space-shift-keying (SSK) modulation technology under imperfect channel state information (CSI). Signal bits are mapped to the indices in the SSK modulation and are transmitted through a single antenna while other antennas remain inactivated. As a result. SSK takes advantages of the location of antennas to modulate signals. At the receiver, the system decides which antenna transmits the signal by observing channel impulse and then demodulates the signal. Research results show that for the same equipment complexity, if the receiver has a full knowledge of the CSI, SSK modulation can achieve satisfactory performance. However, fast changing of wireless channels may cause imperfect and delayed CSI. Meanwhile, space modulation is suspected to be more sensitive to imperfect CSI than traditional modulation.Therefore, in this paper, we simulate and analyze the performance of SSK in fast fading channel, especially on the condition with the imperfect CSI. To obtain the imperfect channel, estimation error is introduced to achieve the purpose of simulating such phenomenon. We also take the channel error power into consideration because of the randomness of channel interference.Simulation results show that the performance of system grows better when the numbers of transmit-antenna or receive-antenna increases if receiver possesses only imperfect CSI. Moreover, performance will also get better when the signal-to-noise ratio (SNR) increases in the same condition. However, the system will remain stable when SNR increases to a certain degree which means adding the SNR is not enough to improve system performance. Last but not the least, the number of transmit-antenna has limited power to improve the performance of system when receive-antennas are certain. While increasing the number of receive antennas can improve the performance dramatically for perfect CSI, the channel estimation error will restrict the improvement of the system performance. |
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