Hello Gents (and Ladies),
I have a project where my mailbox should indicate when it is visited by the newspaper boy. In order to keep things simple, I am using Schmitt trigger oscillator to drive FS1000a transmitter to send the signal indoor (ca. 30 meters). Unfortunately, the signal level indoor is too low due to distance and aluminum lining the in insulation materials in the building, so the signal is largely lost in the noise. I've tried to run Goertzel signal detection algorithm in the Arduino Nano in the receiver section, but to no avail. However, as I want to send only one bit of information (The Mail ! The mail is here ! Yayyyy !) I started wondering whether some other detection method could be used. Currently I am using ca. 900 Hz signal with transmission time something like 10 sec. Naturally, better antennae might solve the problem but I don't want to fix a 70 cm band yagi antenna in my mailbox 
One thing that comes to mind would be to use 1024 Hz crystal stabilized oscillators in both the transmitter and in the receiver, and program Arduino to look for correlation in the received and reference signal bits.
Does anyone else have come across a similar problem and what was the solution ?