Adaptive multi-channel modem
First Claim
1. An apparatus comprising:
- an adjustable filter operative to filter an input signal with an adjustable bandwidth and to provide an output signal, wherein the adjustable bandwidth is determined based on a selected number of spread spectrum signals, the selected number of spread spectrum signals being selected from a plurality of possible numbers of spread spectrum signals selected for reception;
a digital processor operative to process samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; and
a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize the output signal to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof.
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Accused Products
Abstract
An adaptive multi-channel (AMC) modem that can receive one or multiple spread spectrum signals simultaneously includes an adjustable filter, a ΔΣ ADC, and a digital processor. The adjustable filter filters an input signal with an adjustable bandwidth and provides an output signal comprised of a selected number of spread spectrum signals. The ΔΣ ADC digitizes the output signal and provides data samples. The sampling rate and/or the reference voltage of the ΔΣ ADC may be varied to obtain the desired performance. The digital processor processes the data samples for each spread spectrum signal to recover data sent in that signal. A controller ascertains the operating conditions (e.g., the desired signal level, the undesired signal level, and so on) and selects the number of spread spectrum signals to receive based on the operating conditions, user requirements, and possibly other factors.
19 Citations
36 Claims
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1. An apparatus comprising:
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an adjustable filter operative to filter an input signal with an adjustable bandwidth and to provide an output signal, wherein the adjustable bandwidth is determined based on a selected number of spread spectrum signals, the selected number of spread spectrum signals being selected from a plurality of possible numbers of spread spectrum signals selected for reception; a digital processor operative to process samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; and a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize the output signal to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus comprising:
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means for determining operating conditions for a plurality of spread spectrum signals; means for selecting a particular number of spread spectrum signals for simultaneous reception based on the operating conditions; means for setting a baseband filter bandwidth based on the selected number of spread spectrum signals; means for filtering an input signal with the baseband filter bandwidth to obtain an output signal; means for processing samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; and a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize the output signal to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (18, 19, 20)
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21. A method of receiving data in a wireless communication system, comprising:
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determining operating conditions for a plurality of spread spectrum signals; selecting a particular number of spread spectrum signals for simultaneous reception based on the operating conditions; setting a filter bandwidth of a baseband filter based on the selected number of spread spectrum signals; filtering an input signal with the filter bandwidth to obtain an output signal; processing samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; and digitizing the output signal via a delta-sigma analog-to-digital converter (Δ
Σ
ADC) to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (22, 23, 35)
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24. An apparatus comprising:
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a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize an input analog signal to generate samples; anda controller operative to determine operating conditions for at least one spread spectrum signal selected from a plurality of spread spectrum signals, and to select a sampling rate, a reference voltage, or both the sampling rate and the reference voltage for the Δ
Σ
ADC based on the operating conditions, wherein a bandwidth for the Δ
Σ
ADC depends upon a sampling rate, the Vref voltage or a combination thereof. - View Dependent Claims (25, 26, 27, 28)
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29. An apparatus comprising:
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a controller operative to select a variable number of spread spectrum signals to receive simultaneously based on operating conditions, user requirements, or a combination thereof, wherein the variable number of spread spectrum signals are selectable during a call, each of the variable number of spread spectrum signals occupying a different frequency band; a receiver unit operative to process an input signal and provide an output signal comprising the selected variable number of spread spectrum signals; and a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize the output signal to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (30)
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31. An apparatus comprising:
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a controller operative to select a variable number of spread spectrum signals for at least two services to be received concurrently, each of the selected spread spectrum signals occupying a different frequency band; a receiver unit operative to process an input signal and provide an output signal comprising the selected spread spectrum signals; a processor operative to process samples generated from the output signal for each of the selected spread spectrum signals; and a delta-sigma analog-to-digital converter (Δ
Σ
ADC) operative to digitize the output signal to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (32)
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33. A processing system, comprising:
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an input port; an output port; and a processor configured to; determine operating conditions for a plurality of spread spectrum signals; select a particular number of spread spectrum signals for simultaneous reception based on the operating conditions; set a filter bandwidth of a baseband filter based on the selected number of spread spectrum signals to enable the processing system to;
(1) filter an input signal from the input port with the filter bandwidth to obtain an output signal to output through the output port, and (2) process samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; andset a Δ
Σ
ADC bandwidth by varying either a sampling rate of the Δ
Σ
ADC or a Vref voltage or a combination thereof.
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34. A tangible storage medium having stored thereon processor-executable software instructions configured to cause a processor to perform steps comprising:
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determining operating conditions for a plurality of spread spectrum signals; selecting a particular number of spread spectrum signals for simultaneous reception based on the operating conditions; setting a filter bandwidth based on the selected number of spread spectrum signals to enable a filtration of an input signal with the filter bandwidth to obtain an output signal; processing samples generated from the output signal for each spread spectrum signal among the selected number of spread spectrum signals; and digitizing the output signal via a delta-sigma analog-to-digital converter (Δ
Σ
ADC) to generate the samples, wherein the Δ
Σ
ADC is configured to vary its bandwidth in response to variances in either a sampling rate or a Vref voltage or a combination thereof. - View Dependent Claims (36)
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Specification