초록

An alternating pressure pad including at least two sets of inflatable cells, each set being alternately inflated and deflated, wherein at least one cell in each cell set has for example, circumferential internal membranes or external straps, to accelerate the deflation of the at least one cell.

대표청구항 ▼

An alternating pressure pad including at least two sets of inflatable cells, each set being alternately inflated and deflated, wherein at least one cell in each cell set has for example, circumferential internal membranes or external straps, to accelerate the deflation of the at least one cell. es a

An alternating pressure pad including at least two sets of inflatable cells, each set being alternately inflated and deflated, wherein at least one cell in each cell set has for example, circumferential internal membranes or external straps, to accelerate the deflation of the at least one cell. es and convolutional codes. 9. The device according to claim 7, further comprising: a random access memory (RAM) coupled to the puncturing/carrier identification encoding logic and configured to store the prescribed periodic sequence. 10. The device according to claim 7, wherein the prescribed periodic sequence is stored in a codebook that contains a candidate sequence that has a correlation with a plurality of circularly shifted sequences of the candidate sequence, the bad sequence producing a false detection in a decoder and being different from the candidate sequence and the correlation. 11. A receiving device for receiving a plurality of carriers, comprising: a tuner configured to tune to one of the plurality of carriers; a demodulator configured to extract a data sequence from the one carrier; a carrier identification (ID) module configured to multiply the data sequence with a prescribed periodic sequence to form a watermarked signal, the carrier ID module providing a feedback signal to the tuner to control selection of the plurality of carriers; and a forward error control (FEC) decoder configured to decode selectively the watermarked signal; wherein the carrier ID module comprises: a depuncturer/carrier identifier logic configured to depuncture the watermarked signal; a FEC finite state machine coupled to the depuncturer/carrier identifier logic and configured to adjust depuncturing phase of the watermarked signal; and a channel error monitor module coupled to the decoder and configured to determine whether a channel error rate associated with the received watermarked signal exceeds a predetermined error threshold, the channel error monitor module selectively outputting an out-of-synchronization signal to the FEC finite state machine based upon the determined channel error rate. 12. The device according to claim 11, wherein the demodulator utilizes QPSK (Quadrature Phase Shift Keying), the device further comprising: an I/Q swapper and inverter logic coupled to the FEC finite state machine and configured to control the demodulator based upon a control signal from the FEC finite state machine. 13. The device according to claim 11, further comprising: a random access memory (RAM) coupled to the depuncturer/carrier identifier logic and configured to store the prescribed periodic sequence. 14. A receiving device for receiving a plurality of carriers, comprising: a tuner configured to tune to one of the plurality of carriers; a demodulator configured to extract a data sequence from the one carrier; a carrier identification (ID) module configured to multiply the data sequence with a prescribed periodic sequence to form a watermarked signal, the carrier ID module providing a feedback signal to the tuner to control selection of the plurality of carriers; and a forward error control (FEC) decoder configured to decode selectively the watermarked signal; wherein the prescribed periodic sequence is stored in a codebook that contains a candidate sequence that has a correlation with a plurality of circularly shifted sequences of the candidate sequence, the bad sequence producing a false detection in the decoder and being different from the candidate sequence and the correlation. 15. A communication system utilizing a plurality of carriers in a continuous-mode modem, comprising: a transmitter configured to multiply an encoded signal by a prescribed periodic sequence to form a watermarked signal and to transmit the watermarked signal associated with a particular carrier over a communication channel; and a receiver configured to tune to one of the carriers and to extract a data sequence from the one carrier, the receiver multiplying the data sequence with the prescribed periodic sequence to form another watermarked signal and determining whether the watermarked signals match. 16. The system according to claim 15, wherein the transmitter comprises: a forward error control (FEC) encoder config