Error Analysis of SSK With Euclidean Distance Based Selection Combining

In this paper, we analyze the performance of space shift keying (SSK) modulation scheme with Euclidean distance based selection combining (ED-SC) at the receiver. This scheme utilizes a single radio frequency (RF) chain receiver that selects one out of N
_r
receiver antennas based on the Euclidean distance between the SSK constellation points. In addition to this, the performance of generalized ED based SC (GED-SC) is also analyzed by utilizing two or more RF chains at the receiver. The closed form expressions for the average bit error probability (ABEP) of ED-SC and GED-SC schemes are derived for two transmit and N
_r
receive antennas. Further, the theoretical ABEP analysis of ED-SC is derived for N
_t
> 2. In addition to this, we also derive the diversity order analysis of ED-SC SSK system for N
_t
= 2. From the diversity order analysis, it can be inferred that the diversity order obtained by the ED-SC SSK system is N
_r
. It is observed from the simulation results that the performance of 2 × 4 GED-SC SSK system with two and three RF chains is only slightly worse than the optimal detection with N
_r
= 4. Since only a single RF chain is utilized for signal reception in ED-SC, the receiver complexity of employing N
_RF
RF chains in GED-SC and N
_r
RF chains in optimal detection is greatly reduced. Moreover, the simulation results of the ABEP performance of ED-SC SSK system in imperfect channel state information at the receiver is shown.