Separate ACK back-channel (2200–3400 Hz) to prevent sender self-reception - #15
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…urceNode+AudioWorkletNode modem Agent-Logs-Url: https://github.com/melbinjp/audio_data_transfer/sessions/1374ee17-5de5-4c01-97dc-9d3e0317a426 Co-authored-by: melbinjp <91303803+melbinjp@users.noreply.github.com>
….destroy into finally block Agent-Logs-Url: https://github.com/melbinjp/audio_data_transfer/sessions/1374ee17-5de5-4c01-97dc-9d3e0317a426 Co-authored-by: melbinjp <91303803+melbinjp@users.noreply.github.com>
…f-reception Agent-Logs-Url: https://github.com/melbinjp/audio_data_transfer/sessions/1b60ead0-07f3-4f2d-96b6-6e2cbb87dcf1 Co-authored-by: melbinjp <91303803+melbinjp@users.noreply.github.com>
…e' in waitForAck Agent-Logs-Url: https://github.com/melbinjp/audio_data_transfer/sessions/1b60ead0-07f3-4f2d-96b6-6e2cbb87dcf1 Co-authored-by: melbinjp <91303803+melbinjp@users.noreply.github.com>
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The sender's ACK listener and its outgoing data TX shared the same 4-FSK band (400–1600 Hz), making it possible for the sender's mic to decode its own transmissions as spurious ACKs and corrupt the ARQ flow.
Changes
k=[2,4,6,8]→ 400–1600 Hz; a new ACK back-channel usesk=[11,13,15,17]→ 2200–3400 Hz with a 600 Hz gap between bandsmodem-config.ts— addsACK_K_VALUESandACK_PREAMBLE_TONEfsk-modem.ts— exportsChannelConfiginterface plusDATA_CHANNEL/ACK_CHANNELconstants;TransmitterSessionandstartListeningeach accept an optionalChannelConfig(defaults toDATA_CHANNEL— no breaking change)receiver.ts— ACK frames now transmitted vianew TransmitterSession(ACK_CHANNEL)sender-sm.ts— ACK listener opened withstartListening(cb, ACK_CHANNEL); Goertzel bins tuned exclusively to 2200–3400 Hz so the sender's own 400–1600 Hz output produces zero energy at those bins