Apparatus and method to provide spectrum sharing for two or more RF signals occupying an overlapping RF bandwidth

• US 6,985,545 B2
• Filed: 12/26/2000
• Issued: 01/10/2006
• Est. Priority Date: 12/26/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Teo, Koon H., Wu, Shiquan, Steer, David G.
• Primary Examiner(s): Liu, Shuwang
• Assistant Examiner(s): WANG, TED M
• Application Number:
  US09/746,929
• Publication Number:
  US 20020118784A1
• Time in Patent Office: 1,841 Days
• Field of Search: 455/132, 455/422.1, 375/144, 375/147, 375/316, 375/346, 375/146, 375/349, 375/319, 375/148, 375/134, 375/341, 375/136, 375/130, 375/149, 375/140, 375/265, 375/343, 375/315, 375/143, 370/320, 370/342, 370/335, 370/347, 341/94
• US Class Current: 375/349
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/7105 Joint detection techniques, e.g. linear detectors
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

An RF radio receiver utilizing wideband RF technology, a wideband digital IF (channelizer) tuner, a common digitizing rate, and multi-user detection (MUD) processes a superposed RF signal to allow simultaneous reception of two or more RF signals sharing overlapping frequency spectrum (RF bandwidth). The RF radio receiver is particularly effective for two or more RF signals of differing RF channel bandwidth and can also receive signals which accord to different air interface standards. The use of a common digitizing rate provides for oversampling of at least one of the RF signals for more accurate decoding and allows for a synchronized signal (i.e. at a common rate) to be used in decoding, and in particular multi-user decoding of other RF signals.

Claims

1. A wireless communication receiver for processing a superposed RF (radio frequency) signal containing two or more RF signals occupying overlapping RF bandwidth, the wireless communication receiver comprising:

a wideband receiver for receiving said superposed RF signal;

an analog to digital converter for converting said received superposed RF signal to a superposed digital signal using a common digitizing rate;

a channelizer for each of said RF signals that receives said superposed digital signal and limits said superposed digital signal to a bandwidth that corresponds with the bandwidth of each of said RF signals, providing a bandwidth clipped digital signal for each of said RF signals; and

a signal handling device for each of said RF signals that receives one said bandwidth clipped digital signal, said signal handling device comprising;

a multi-user detection decoder that shares data with multi-user detection decoders in other ones of said signal handling device to decode said bandwidth clipped digital signal to remove conventional and multi-access interference and provide a decoded digital signal; and

a rate adjuster that adjusts a sampling rate of said decoded digital signal to provide an output signal having a predetermined sampling rate.

2. The wireless communication receiver of claim 1, wherein each said channelizer includes a rate adjuster that adjusts a sampling rate of said superposed digital signal to an adjusted common digitizing rate, wherein said adjusted common digitizing rate is a reduced multiple of each said predetermined sampling rate.

3. The wireless communication receiver of claim 1 wherein at least one signal handling device includes a stream separator for forming separate streams from said bandwidth clipped digital signal, each stream based on a set of samples from said bandwidth clipped digital signal at said predetermined sampling rate and wherein said multi-user detection decoder decodes said bandwidth clipped digital signal responsive to said streams.

4. The wireless communication receiver of claim 3, wherein all but said signal handling device for said RF signal having the largest bandwidth is provided with said stream separator.

5. The wireless communication receiver of claim 1, wherein said common digitizing rate is determined such that said receiver can process a superposed RF signal containing RF signals associated with two or more air interface standards.

6. The wireless communication receiver of claim 1, wherein said two or more RF signals comprise voice and data signals.

7. A wireless communication receiver for processing a superposed RF (radio frequency) signal containing two or more RF signals occupying overlapping RF bandwidth, the wireless communication receiver comprising:

a wideband receiver for receiving said superposed RF signal;

an analog to digital converter for converting said received superposed RF signal to a superposed digital signal using a previously determined common digitizing rate;

a channelizer for at least a first RF signal having the smallest bandwidth of said RF signals that receives said superposed digital signal and limits said superposed digital signal to a bandwidth that corresponds with the bandwidth of each of said at least said first RF signal of said RF signals, providing at least one bandwidth clipped digital signal;

a first signal handling device for said first RF signal that receives a first respective bandwidth clipped digital signal, comprising;

a first decoder that removes interference and decodes said first respective bandwidth clipped digital signal to provide a first decoded signal representing said first RF signal; and

a rate converter that converts the sample rate of said first decoded signal to a first standard DSP rate for the said first RF signal; and

a signal handling device for said each RF signal, other than said first RF signal, that receives one of said superposed digital signal and respective said at least one bandwidth clipped digital signal, comprising;

a multi-user detection decoder that receives said first decoded signal from said first decoder of said first signal handling device and shares data with multi-user detection decoders in any other signal handling devices to remove conventional and multi-access interference and decode said one of said superposed digital signal and respective said at least one bandwidth clipped digital signal to provide a decoded signal for said each RF signal; and

a rate adjuster that adjusts the sampling rate of said decoded signal for said each RF signal to a standard DSP rate for said each RF signal.

8. The wireless communication receiver of claim 7, wherein each said channelizer includes a rate reducer that reduces a sampling rate of said superposed digital signal to a reduced common digitizing rate which is a reduced multiple of said first standard DSP rate and a standard DSP rate for said each RF signal.

9. The wireless communication receiver of claim 8, wherein said first signal handling device includes a stream separator for forming separate streams from said first bandwidth clipped digital signal, each stream based on a set of samples from said first bandwidth clipped digital signal at said first standard DSP rate, and wherein said decoder decodes said first bandwidth clipped digital signal using said streams.

10. The wireless communication receiver of claim 7, wherein said common digitizing rate is determined such that said receiver can process a superposed RF signal containing RF signals associated with two or more air interface standards.

11. The wireless communication receiver of claim 7, wherein said two or more RF signals comprise voice and data signals.