Acoustic communication system
First Claim
1. A toy system comprising an encoder for encoding a data signal within an audio track to form a modified audio track, an electro-acoustic transducer for converting the modified audio track into a corresponding acoustic signal, and a toy responsive to the acoustic signal, wherein:
- the encoder comprises;
(i) a first receiver operable to receive the data signal, the data signal defining a sequence of data symbols, the data signal having a data signal bandwidth, defined by a symbol duration of the data symbols, that is centered around a first frequency;
(ii) a spreader operable to spread the received data signal or a carrier signal modulated with the received data signal to form a spread signal having a signal bandwidth greater than the data signal bandwidth;
(iii) a modulator operable either;
a) to use the data signal, before being spread by said spreader, to modulate at least one separate periodic carrier signal, whose period is smaller than the symbol duration of the data symbols, to form a modulated carrier signal such that, after spreading by the spreader, a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from the first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz;
orb) to use the spread signal to modulate at least one separate periodic carrier signal, whose period is smaller than the symbol duration of the data symbols, such that a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from the first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz;
(iv) a second receiver operable to receive an audio track;
(v) a combiner operable to combine the spread and modulated signal with the audio track to generate a modified audio track; and
(vi) an output operable to output the modified audio track,and wherein the toy comprises;
(i) an acousto-electric transducer operable to receive and convert the acoustic signal into a corresponding electrical signal;
(ii) a decoder operable to de-spread and demodulate the electrical signal obtained from said acousto-electric transducer, in order to regenerate the data signal; and
(iii) a responder responsive to the data signal.
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Accused Products
Abstract
A signalling system is provided which can be used to update the prices of goods which are electronically displayed on supermarket shelves (1). The signalling system comprises a first signalling device having an input terminal for receiving electrical message data received from a central computer system (5), a spread spectrum encoder for encoding the received message data and an electroacoustic converter (11) for converting the encoded data into corresponding acoustic signals and for transmitting the acoustic signals into a transmission medium. The signalling system also comprises a second signalling device (3) having means for receiving acoustic signals from said transmission medium and for converting the received acoustic signals into corresponding electrical signals, a spread spectrum decoder for decoding the received signals and a message regenerator for regenerating the message data transmitted by the first signalling device from the signals output by the decoder.
127 Citations
57 Claims
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1. A toy system comprising an encoder for encoding a data signal within an audio track to form a modified audio track, an electro-acoustic transducer for converting the modified audio track into a corresponding acoustic signal, and a toy responsive to the acoustic signal, wherein:
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the encoder comprises; (i) a first receiver operable to receive the data signal, the data signal defining a sequence of data symbols, the data signal having a data signal bandwidth, defined by a symbol duration of the data symbols, that is centered around a first frequency; (ii) a spreader operable to spread the received data signal or a carrier signal modulated with the received data signal to form a spread signal having a signal bandwidth greater than the data signal bandwidth; (iii) a modulator operable either; a) to use the data signal, before being spread by said spreader, to modulate at least one separate periodic carrier signal, whose period is smaller than the symbol duration of the data symbols, to form a modulated carrier signal such that, after spreading by the spreader, a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from the first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz;
orb) to use the spread signal to modulate at least one separate periodic carrier signal, whose period is smaller than the symbol duration of the data symbols, such that a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from the first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz; (iv) a second receiver operable to receive an audio track; (v) a combiner operable to combine the spread and modulated signal with the audio track to generate a modified audio track; and (vi) an output operable to output the modified audio track, and wherein the toy comprises;
(i) an acousto-electric transducer operable to receive and convert the acoustic signal into a corresponding electrical signal;
(ii) a decoder operable to de-spread and demodulate the electrical signal obtained from said acousto-electric transducer, in order to regenerate the data signal; and
(iii) a responder responsive to the data signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
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57. A method of controlling a toy, the method comprising the steps of:
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receiving, at a control center, a data signal defining a sequence of data symbols, the data signal having a data signal bandwidth, defined by a symbol duration of said data symbols, that is centered around a first frequency; spreading the received data signal or a carrier signal modulated with the received data signal to form a spread signal having a signal bandwidth greater than said data signal bandwidth; either; a) using the data signal before being spread in said spreading step to modulate at least one separate periodic carrier signal, having a period which is smaller than said symbol duration, to form a modulated carrier signal such that, after spreading in said spreading step, a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from said first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz;
orb) using the data signal after being spread in said spreading step to modulate at least one separate periodic carrier signal, having a period which is smaller than said symbol duration, such that a main band of a power spectrum of the spread and modulated signal is centered around a second frequency that is different from said first frequency and that lies within an audible frequency band of 20 Hz and 20 kHz; combining the spread and modulated signal with an audio track to form a modified audio track; transmitting the modified audio track to an electro-acoustic transducer in the vicinity of the toy; converting the modified audio track into an acoustic signal at the electro-acoustic transducer; receiving the acoustic signal at the toy; converting the acoustic signal received by the toy into an electrical signal; de-spreading and demodulating the electrical signal obtained by converting the acoustic signal to generate a de-spread signal; regenerating the data signal from the demodulated and de-spread signal; and controlling the toy in accordance with a content of the data signal.
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Specification