From that code, it looks like a regular TCP connection. "websocket" means something different. For TCP connections, use the free TCP/UDP/IP toolbox found here:
http://www.mathworks.com/matlabcentral/fileexchange/345-tcpudpip-toolbox-2-0-6
It is at least as good as the official network tools provided in MATLAB's Instrument Control Toolbox.
Equivalent code will look something like this:
con=pnet('tcpconnect','192.168.0.111', 9090);
pnet(con,'printf','raw\r\n\r\n');
pnet(con,'close');