Code synchronization for analog spread spectrum systems
First Claim
1. A method for performing synchronization in a receiver of an analog code division spreading system, the method comprising:
- outputting at least one sampling point alignment signal to apply one or more determined first time delays to encoder code signals, the encoder code signals carrying encoder codes used by an encoder for generating an orthogonal code-encoded analog signal, the one or more first time delays being determined to align the encoder code signals with a sampling point of an analog-to-digital converter (ADC), the ADC being used to obtain digital samples of the orthogonal code-encoded analog signal at the sampling point;
outputting at least one decoder code alignment signal to apply one or more determined second time delays to decoder code signals, the decoder code signals carrying decoder codes used by a decoder for decoding the digital samples, the one or more second time delays being determined to align the decoder code signals with the digital samples; and
outputting at least one orthogonal code alignment signal to apply one or more determined third time delays to the decoder code signals and the encoder code signals, the one or more third time delays being determined to maintain mutual orthogonality among the decoder code signals and to maintain mutual orthogonality among the encoder code signals.
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Abstract
Methods and apparatuses for performing synchronization in a receiver of an analog code division spreading system are described. The method includes outputting a sampling point alignment signal to apply first time delays to align encoder code signals with a sampling point of an ADC The ADC is used to obtain digital samples of the orthogonal code-encoded analog signal at the sampling point. The method also includes outputting a decoder code alignment signal to apply second time delays to align decoder code signals with the digital samples. The method also includes outputting an orthogonal code alignment signal to apply third time delays to the decoder code signals and the encoder code signals, to maintain mutual orthogonality among the decoder code signals and to maintain mutual orthogonality among the encoder code signals.
57 Citations
20 Claims
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1. A method for performing synchronization in a receiver of an analog code division spreading system, the method comprising:
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outputting at least one sampling point alignment signal to apply one or more determined first time delays to encoder code signals, the encoder code signals carrying encoder codes used by an encoder for generating an orthogonal code-encoded analog signal, the one or more first time delays being determined to align the encoder code signals with a sampling point of an analog-to-digital converter (ADC), the ADC being used to obtain digital samples of the orthogonal code-encoded analog signal at the sampling point; outputting at least one decoder code alignment signal to apply one or more determined second time delays to decoder code signals, the decoder code signals carrying decoder codes used by a decoder for decoding the digital samples, the one or more second time delays being determined to align the decoder code signals with the digital samples; and outputting at least one orthogonal code alignment signal to apply one or more determined third time delays to the decoder code signals and the encoder code signals, the one or more third time delays being determined to maintain mutual orthogonality among the decoder code signals and to maintain mutual orthogonality among the encoder code signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for performing synchronization in a receiver of an analog code division spreading system, the apparatus comprising:
a synchronizer configured to; receive, from an analog-to-digital converter (ADC), digital samples of an orthogonal code-encoded analog signal, the digital samples being obtained by the ADC at a sampling point; output at least one sampling point alignment signal to apply one or more determined first time delays to encoder code signals, the encoder code signals being used by an encoder for generating the orthogonal code-encoded analog signal, the one or more first time delays being determined to align the encoder code signals with the sampling point of the ADC; output at least one decoder code alignment signal to apply one or more determined second time delays to decoder code signals, the decoder code signals being used by a decoder for decoding the digital samples, the one or more second time delays being determined to align the decoder code signals with the digital samples; and output at least one orthogonal code alignment signal to apply one or more determined third time delays to the decoder code signals and the encoder code signals, the one or more third time delays being determined to maintain mutual orthogonality among the decoder code signals and to maintain mutual orthogonality among the encoder code signals. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A receiver in an analog code division spreading system, the receiver comprising:
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a plurality of receiving paths for receiving respective analog signals, each receiving path including a respective orthogonal code-encoder to perform encoding using a respective encoder code signal; a combiner for combining a plurality of signals outputted by the orthogonal code-encoders into a combined orthogonal code-encoded analog; an analog-to-digital converter (ADC) for obtaining digital samples of the combined orthogonal code-encoded analog signal at a sampling point; and a decoder for decoding the digital samples using decoder code signals, the decoder comprising a synchronizer configured to; output at least one sampling point alignment signal to apply one or more determined first time delays to the encoder code signals, the one or more first time delays being determined to align the encoder code signals with the sampling point of the ADC; output at least one decoder code alignment signal to apply one or more determined second time delays to the decoder code signals, the one or more second time delays being determined to align the decoder code signals with the digital samples; and output at least one orthogonal code alignment signal to apply one or more determined third time delays to the decoder code signals and encoder code signals, the one or more third time delays being determined to maintain mutual orthogonality among the decoder code signals and to maintain mutual orthogonality among the encoder code signals. - View Dependent Claims (19, 20)
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Specification