if you want to store the variable names Testsignal_1 and Current then you need to use an indexing variable as below. If this code snippet is present in a bigger code structure which is repeated several times, then the index helps to store the variable names and signals for each run/ iteration. In your code, the name of the signal and variables are not character vectors but defined by a value.
If the if-end condition is not satisfied, then the signal and variable names will NOT appear in workspace. The below code will store both signal and variable names and would appear in workspace if the condition is satisfied.
k = 1; % iterator index
if(exist('Testsignal_1','var'))
Current{k}='Testsignal_1'; % signal name as character vector stored in cell array
k = k+1; % increment
end
keepvars(end+1) = Current; % store or assign the cell array to keepvars data array present in bigger code structure
