Good question. A good but short answer is given on Wikipedia (https://en.wikipedia.org/wiki/Matched_filter#Matched_filter_in_digital_communications https://en.w

Good question. A good but short answer is given on Wikipedia (https://en.wikipedia.org/wiki/Matched_filter#Matched_filter_in_digital_communications https://en.wikipedia.org/wiki/Matched_filter#Matched_filter_...). Any undergraduate textbook on digital signal processing should have details on this topic. edit: to add to this, the capacity C ("throughput") of the communications channel is linear with bandwidth B (in Hertz) but only logarithmic (log_2) with noise power N. This was derived by Shannon (https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem#Statement_of_the_theorem https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...) and in equation form: C = B*log_2(1+S/N) Example: signal to noise ratio is 1 (S/N = 1). Result: C = B Now we increase the bandwidth of our channel by a factor of 10, keeping the signal power equal. This will lead to a factor 10 more noise power (S/N = 1/10). Result: C = 10*B*log_2(1 + 1/10) = 1.38*B So we can improve the channel capacity by increasing the bandwidth even in a noisy channel.