Wireless Speed Problem

I have a Linksys WRT54G wireless router. I have a HP Pavillion DV5000 Laptop. I have cable service for internet. When I use my wireless router for my laptop, I get 1.5 mbps for a download speed. When I use my wired connection, I get over 5mbsp. How can I get the wireless speed closer to the 5. I know I probably won't be able to get 5, but I think I should get more. My connection speed for the wireless route shows 54.0 mbps in my taskbar. I use Windows XP, AVG Virus, Comodo Spyware. Thanks in advance for the help