252results about "Pulse combined modulation" patented technology

[Problems] To realize a reliable and stable transfer of digital data that does not require a reference clock and a handshake operation.[Means for Solving the Problem] The present invention provides a digital data transfer method for alternately and periodically transferring first information and second information respectively in a first period and in a second period, wherein: an amount of information of the first information per unit time in the first period is greater than an amount of information of the second information per unit time in the second period; and the second information in the first period is transferred as pulse-width-modulated serial data.

A digital communications transmitter (100) includes a digital linear-and-nonlinear predistortion section (200, 1800, 2800) to compensate for linear and nonlinear distortion introduced by transmitter-analog components (120). A direct-digital-downconversion section (300) generates a complex digital return-data stream (254) from the analog components (120) without introducing quadrature imbalance. A relatively low resolution exhibited by the return-data stream (254) is effectively increased through arithmetic processing. Distortion introduced by an analog-to-digital converter (304) may be compensated using a variety of adaptive techniques. Linear distortion is compensated using adaptive techniques with an equalizer (246) positioned in the forward-data stream (112). Nonlinear distortion is then compensated using adaptive techniques with a plurality of equalizers (226) that filter a plurality of orthogonal, higher-ordered-basis functions (214) generated from the forward-data stream (112). The filtered-basis functions are combined together and subtracted from the forward-data stream (112).

A communication system that uses keyed modulation to encode fixed frequency communications on a variable frequency power transmission signal in which a single communication bit is represented by a plurality of modulations. To provide a fixed communication rate, the number of modulations associated with each bit is dynamic varying as a function of the ratio of the communication frequency to the carrier signal frequency. In one embodiment, the present invention provides dynamic phase-shift-keyed modulation in which communications are generated by toggling a load at a rate that is a fraction of the power transfer frequency. In another embodiment, the present invention provides communication by toggling a load in the communication transmitter at a rate that is phase locked and at a harmonic of the power transfer frequency. In yet another embodiment, the present invention provides frequency-shift-keyed modulation, including, for example, modulation at one of two different frequencies.

In an adaptive modulation and coding method one or more adjustable values are created (S1), each corresponding to at least one of a plurality of available modulation and coding levels applicable to a signal transmitted from a transmitter to a receiver, and each representing a change to the level(s) to which it corresponds. One or more of said adjustable values is / are adjusted in dependence upon whether or not the signal is received successfully by the receiver (S2-S5). One of said available modulation and coding levels is selected (S6-S8) to apply to the signal based on such an adjustable value. Such a method can enable the appropriate modulation and coding level to be selected even when the path and channel conditions vary. The method is applicable to selecting modulation and coding levels in a high-speed downlink packet access system of a wireless communication network.

A digital communications transmitter (100) includes a digital linear-and-nonlinear predistortion section (200) to compensate for linear and nonlinear distortion introduced by transmitter-analog components (120). A direct-digital-downconversion section (300) generates a complex digital return-data stream (254) from the analog components (120) without introducing quadrature imbalance. A relatively low resolution exhibited by the return-data stream (254) is effectively increased through arithmetic processing. Linear distortion is first compensated using adaptive techniques with an equalizer (246) positioned in the forward-data stream (112). Nonlinear distortion is then compensated using adaptive techniques with a plurality of equalizers (226) that filter a plurality of orthogonal, higher-ordered-basis functions (214) generated from the forward-data stream (112). The filtered-basis functions are combined together and subtracted from the forward-data stream (112).

Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

A digital communications transmitter (100) includes a digital linear-and-nonlinear predistortion section (200, 1800) to compensate for linear and nonlinear distortion introduced by transmitter-analog components (120). A direct-digital-downconversion section (300) generates a complex digital return-data stream (254) from the analog components (120) without introducing quadrature imbalance. A relatively low resolution exhibited by the return-data stream (254) is effectively increased through arithmetic processing. Distortion introduced by an analog-to-digital converter (304) may be compensated using a variety of adaptive techniques. Linear distortion is compensated using adaptive techniques with an equalizer (246) positioned in the forward-data stream (112). Nonlinear distortion is then compensated using adaptive techniques with a plurality of equalizers (226) that filter a plurality of orthogonal, higher-ordered-basis functions (214) generated from the forward-data stream (112). The filtered-basis functions are combined together and subtracted from the forward-data stream (112).

An apparatus for coding a pseudo orthogonal space-time block code in a transmitter using 4 transmission antennas of first to fourth transmission antennas. Upon receiving information symbol streams x1x2x3x4 to be transmitted, a serial-to-parallel converter parallel-converts the received information symbol streams x1x2x3x4 into x1,x2,x3,x4. A pseudo orthogonal space-time block coding (PO-STBC) encoder codes the parallel-converted information symbol streams x1,x2,x3,x4 using a pseudo orthogonal space-time block coding scheme such that the information symbol streams x1,x2,x3,x4 are transmitted via corresponding transmission antennas for first to fourth time periods.