摘要:
A system, method and computer program product for positioning pulses, including positioning pulses within a specified time layout according to one or more codes to produce a pulse train having one or more predefined spectral characteristics where a difference in time position between adjacent pulses positioned to produce a spectral characteristic differs from another difference in time position between other adjacent pulses positioned to produce the spectral characteristic. The present invention may include shaping a code spectrum according to a spectral template in order to preserve a pre-defined code characteristic. A pre-defined code characteristic can include desirable correlation, or spectral properties. A transmitter incorporating the present invention can avoid transmitting at a particular frequency. Similarly, a receiver can avoid interference with a signal transmitting at a particular frequency. A radar system, can avoid a radar jammer attempting to jam a particular frequency.
摘要:
The present invention relates to a method for generating and apparatus for employing code families having desirable correlation properties. Regardless of code length, maximum autocorrelation of the codes is 4 for any nonzero offset and maximum cross-correlation of any two codes from a code family is 4 for any offset. The codes can be used in impulse radio systems and non-impulse radio systems including CDMA, TDMA, FDMA, OFDM and various other frequency hopping and direct sequence systems. The codes can be used to specify various impulse radio and non-impulse radio signal characteristics including pulse position in time, amplitude, width, type, phase, phase difference, frequency, spreading code, etc. The codes have the unique property that they can specify as many as two components in which a signal is not present. A method of code compression is provided.
摘要:
A method for specifying pulse characteristics applies codes having pre-defined characteristics to a layout. The layout can be sequentially subdivided into at least first and second components that have the same or different sizes. The method applies a first code having first pre-defined properties to the first component and a second code having second pre-defined properties to the second component. The pre-defined properties may relate to the auto-correlation property, the cross-correlation property, and spectral properties, as examples. The codes can be used to specify subcomponents within a frame, and characteristic values (range-based, or discrete) within the subcomponents.
摘要:
A set of piconets and corresponding methods and computer programs may reduce contention time between piconets. In one embodiment, a seven-length code architecture may be used with group(s) of bands so that contention time cannot exceed 1/7 of the time. Up to seven different bands can be used within each group. When less than seven bands are used (e.g., three or six), at least one of the bands may be assigned to more than one dwell time during a time span. Alternatively, each dwell time within the time span may be assigned to a different band. The state may be changed as needed or desired. Substitution of extra bands may also be used. Using either scheme (repeated bands or changing states), a prime-number architecture can be used with a non-prime number of different bands. Simultaneous communications using at least two bands within a piconet may be used.
摘要:
A set of piconets and corresponding methods and computer programs may reduce contention time between piconets. In one embodiment, a seven-length code architecture may be used with group(s) of bands so that contention time cannot exceed 1/7 of the time. Up to seven different bands can be used within each group. When less than seven bands are used (e.g., three or six), at least one of the bands may be assigned to more than one dwell time during a time span. Alternatively, each dwell time within the time span may be assigned to a different band. The state may be changed as needed or desired. Substitution of extra bands may also be used. Using either scheme (repeated bands or changing states), a prime-number architecture can be used with a non-prime number of different bands. Simultaneous communications using at least two bands within a piconet may be used.
摘要:
A system and method of implementing precision time delays that provides important and novel improvements over prior techniques of implementing time delays by utilizing a new strategy for selecting the values in the sine and cosine lookup tables. Sine and cosine values which result in non-uniform amplitudes enable increased overall accuracy with fewer bits communicated from the look-up tables to the analogue portion of the system. Further, herein is provided the addition of a variable amplitude threshold crossing capability following the combining of the sine and cosine signals. The time delay accuracy of the resulting phase and amplitude hybrid system can be improved either by increasing the number of bits in the sine/cosine phase management section or by increasing the number of bits in the amplitude section. There is provided herein an optimum strategy for choosing the number of bits used in the phase and amplitude sections for the best overall delay accuracy with the fewest overall control bits.
摘要:
A coding method for a pulse transmission system specifies temporal and/or non-temporal pulse characteristics according to temporal and/or non-temporal characteristic value layouts having one or more allowable and non-allowable regions. The method generates codes having predefined properties. The method generates a pulse train by mapping codes to the characteristic value layouts, where the codes satisfy predefined criteria. In addition, the predefined criteria can limit the number of pulse characteristic values within a non-allowable region. The predefined criteria can be based on relative pulse characteristic values. The predefined criteria can also pertain to spectral properties and to correlation properties. The predefined criteria may pertain to code length and to the number of members of a code family. The pulse train characteristics may pertain to a subset of the pulse train.
摘要:
A method for generating code sequences having good correlation properties comprising steps of selecting a code length comprising a number of chips, selecting a ruler which defines the position of non-zero values within the chips, and overlaying the non-zero values with an amplitude pattern.
摘要:
A method for generating code sequences having good correlation properties comprising steps of selecting a code length comprising a number of chips, selecting a ruler which defines the position of non-zero values within the chips, and overlaying the non-zero values with an amplitude pattern.
摘要:
A set of piconets and corresponding methods and computer programs may reduce contention time between piconets. In one embodiment, a seven-length code architecture may be used with group(s) of bands so that contention time cannot exceed 1/7 of the time. Up to seven different bands can be used within each group. When less than seven bands are used (e.g., three or six), at least one of the bands may be assigned to more than one dwell time during a time span. Alternatively, each dwell time within the time span may be assigned to a different band. The state may be changed as needed or desired. Substitution of extra bands may also be used. Using either scheme (repeated bands or changing states), a prime-number architecture can be used with a non-prime number of different bands. Simultaneous communications using at least two bands within a piconet may be used.