We propose an asynchronous acoustic chirp slope keying to map short bit sequenceson single or multiple bands without preamble or error correction coding on the physical layer.

We introduce a symbol detection scheme in the demodulator that uses the superposed matchedfilter results of up and down chirp references to estimate the symbol timing, which removes therequirement of a preamble for symbol synchronization. Details of the implementation are disclosedand discussed, and the performance is verified in a pool measurement on laboratory scale, as wellas the simulation for a channel containing Rayleigh fading and Additive White Gaussian Noise.

For time-bandwidth products (TB) of 50 in single band mode, a raw data rate of 100 bit/s is simulatedto achieve bit error rates (BER) below 0.001 for signal-to-noise ratios above ?6 dB. In dual-band mode,for TB of 25 and a data rate of 200 bit/s, the same bit error level was achieved for signal-to-noiseratios above 0 dB. The simulated packet error rates (PER) follow the general behavior of the BER, butwith a higher error probability, which increases with the length of bits in each packet.