Hello Giovanni
Yes, a port channel would be a solution to such a problem, but not an ideal one. Etherchannel will only increase the uplink speed by the number of physical links that are available. Much higher throughput will be achieved by using faster interfaces, because the increase in speed is usually 10 times. For example, Gigabit Ethernet is 10 times faster than FastEthernet, and 10G interfaces are 10 times faster than GigabitEthernet… and so on.
But definitely, in the absence of any other solution, etherchannel is a good solution.
I hope this has been helpful!
Laz