Combining two Internet Connections WIFI and Wirless for internet speed

Combining two Internet Connections WIFI and Wirless for internet speed on a pc and lan
USB Wifi Connection speed = 1024 kbps Download
USB Wireless dongle speed = 512 kbps Download
I would love to combine those so I would get at least in a range of 1.5MB Download and faster upload.

Is Merging the 2 together to form a stronger connection would work ?.
I also have a DLINK 618 Router for Lan and wireless .So I want both USB on the pc to receive data and from there it should go to Router for other lan pcs.Individually ther are working but I think some setting in the IP is not making them to work togther. any help ? waiting for reply