Signal bandwidth and channel bandwidth
No problem at all if $B_s \ll B_c$.
However, $B_s = 10\text{Hz}$ is considerably small that makes synchronization very difficult especially for low-cost receivers.
For example, Sigfox Ultra Narrow Band uses $10\text{Hz}$ bandwidth (are you studying the standard?) that requires precise but expensive oscillators like TCXO. Even with that, there must be random access enhancement to deal with the frequency imprecision.
There is also some effort to design transceivers without TCXO for such narrow bandwidth. Check e.g. Foxy.