Wifi is not working on Dell Inspiron 15 5570

I am having Dell inspiron 15 5570 laptop. I have windows10 and ubuntu 14.04LTS. Wifi is not automatically detected and connected in ubuntu. In windows 10 wifi is automatically connected. I have tried by installing bmwcl kernel source and b43 firmware. But it is not helpful. Kindly help me to work my laptop wifi in ubuntu os as well. Thanks.