초록 ▼

A method for compensating for multipath components in a received CDMA signal comprising a repetitive PRN code uses delay times in addition to the early, late and prompt delay times for determining if a multipath component is present in the received signal, and if so, making an adjustment to the dela

A method for compensating for multipath components in a received CDMA signal comprising a repetitive PRN code uses delay times in addition to the early, late and prompt delay times for determining if a multipath component is present in the received signal, and if so, making an adjustment to the delay time of the replica code generated by a receiver so as to minimize the difference between the correlation values for a delay time equal to -1 chip and a delay time more negative than -1 chip. In this manner, adjustments to the estimation time for the start of the PRN code can be made in a manner which minimizes the effects of multipath components. A system using additional delays and correlators in association with the code phase detector, a code numerical control oscillator and replica code generator is described for performing the above methodology. The methodology is particularly suitable for GPS receivers and may further be used in receivers that receive any type of digital sequence spread spectrum, code division multiple access signals. Compensation for multipath components with 180 degree phase shifts is also made as well as compensation due to smoothing of the triangular correlation function due to RF characteristics and non-ideal PRN codes.

대표청구항 ▼

A method for compensating for multipath components in a received CDMA signal comprising a repetitive PRN code uses delay times in addition to the early, late and prompt delay times for determining if a multipath component is present in the received signal, and if so, making an adjustment to the dela

A method for compensating for multipath components in a received CDMA signal comprising a repetitive PRN code uses delay times in addition to the early, late and prompt delay times for determining if a multipath component is present in the received signal, and if so, making an adjustment to the delay time of the replica code generated by a receiver so as to minimize the difference between the correlation values for a delay time equal to -1 chip and a delay time more negative than -1 chip. In this manner, adjustments to the estimation time for the start of the PRN code can be made in a manner which minimizes the effects of multipath components. A system using additional delays and correlators in association with the code phase detector, a code numerical control oscillator and replica code generator is described for performing the above methodology. The methodology is particularly suitable for GPS receivers and may further be used in receivers that receive any type of digital sequence spread spectrum, code division multiple access signals. Compensation for multipath components with 180 degree phase shifts is also made as well as compensation due to smoothing of the triangular correlation function due to RF characteristics and non-ideal PRN codes. ally coupled to an optical cavity of the laser, a detector optically coupled to the laser to measure the power of light output from the laser, and a processor electronically coupled to the detector and to the wavelength selector. The processor adjusts the wavelength selector through a series of discrete steps and receives a power measurement from the detector at each of the steps. The processor performs statistical analyses on the power measurements, and, based on the statistical analyses, the wavelength selector is adjusted to selectively pass a wavelength that approximately corresponds to a peak of a desired spectral line. ing of the portion of the content object between the plurality of channels and the server recited in claim 9, wherein: the first party provides the bandwidth for at least a portion of the first datapath, and the second party provides the bandwidth for at least a portion of the second datapath. 16. The method for routing of the portion of the content object between the plurality of channels and the server recited in claim 9, wherein the server is comprised of a plurality of computer systems. 17. A system routing of a portion of a content object between a plurality of data channels and a first server, the system comprising: a first data channel for the first server, wherein the first data channel is associated with a first provider; a second data channel for the first server, wherein the second data channel is associated with a second provider; a second server with a plurality of content objects, wherein the first server stores at least a portion of one of the plurality of content objects; and a router that automatically determines which of the first and second data channels to transport the portion of the content object with, wherein the determination is performed away from the first server. 18. The system routing of the portion of the content object between the plurality of data channels and the first server as recited in claim 17, further comprising a plurality of unique identifiers for the first server, wherein the first and second data channels are logically isolated by marking packets with one of the plurality of unique identifiers. 19. The system routing of the portion of the content ob