Systems and methods for wireless communications

• US 20040156449A1
• Filed: 11/21/2003
• Published: 08/12/2004
• Est. Priority Date: 01/13/1998
• Status: Abandoned Application

• Current Assignee: Alok B. Shah, David L. Tennenhouse, John V. Gutag, Matthew Welborn, Michael Ismert, Vanu G. Bose
• Original Assignee: Alok B. Shah, David L. Tennenhouse, John V. Gutag, Matthew Welborn, Michael Ismert, Vanu G. Bose
• Inventors: Ismert, Michael, Tennenhouse, David L., Bose, Vanu G., Shah, Alok B., Gutag, John V., Welborn, Matthew
• Application Number:
  US10/719,643
• Publication Number:
  US 20040156449A1
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/0007 wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
• CPC Class Codes: H04B 1/001 Channel filtering, i.e. selecting a frequency channel within the SDR system multiplexing of multicarrier modulation signals being represented by different frequencies H04L5/06; multiplexing of multicarrier modulation signals H04L5/023
• CPC Class Codes: H04B 1/0017 Digital filtering H04B1/001 takes precedence; digital filters per se H03H17/00
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 74/00 Wireless channel access

Abstract

The invention provides systems and methods that include, inter alia, wireless communication systems that integrate wireless receivers and transmitters with host computer platforms and that include a data access channel that delivers into the memory space of an application program digital data that is representative of a base band modulated signal. Accordingly, these systems can employ wideband digitization of an incoming signal, such as an RF signal, direct the digitized data into the application memory space of a general purpose workstation, and allow an application program operating on the general purpose work station to perform the digital signal processing that obtains the information encoded within the digitized signal.

Claims

1. A method of processing radio signals, comprising

converting between a wideband signal and a high sampling rate digital signal,

under control of a direct memory access controller in communication with a processor, storing samples of the high sampling rate digital signal directly into an application memory space without interrupting the processor, said application memory space being accessible by a computer program;

processing the high sampling rate digital signal samples under control of the computer program.

2. The method of claim 1, wherein sampling is continuous.

3. The method of claim 1, wherein samples are stored at a rate equal to the sampling rate.

4. The method of claim 1, wherein the wideband signal has a bandwidth of 10 MHZ and sampling rate is at least 20 mega-samples per second.

5. The method of claim 1, wherein processing further comprises modulating a signal to the digitized IF signal.

6. The method of claim 1, wherein processing further comprises demodulating a signal from the digitized IF signal.

7. The method of claim 1, wherein processing further comprises channel selection.

8. The method of claim 1, wherein storing samples under control of the direct memory access controller comprises:

maintaining, in the direct memory access controller, a list of physical page addresses associated with buffers in memory;

reading a page address from the list,

transferring, between an input/output device and memory to which the page address is associated, the high sampling rate digital signal samples; and

repeating continuously the above reading and transferring steps.

9. The method of claim 8, wherein storing samples under control of the direct memory access controller further comprises:

removing the page address from the list; and

providing new page addresses by interrupting the processor when the number of page addresses in the list falls below a predetermined threshold, such that an interrupt handler provides the new page addresses.

10. A method for processing a radio signal, comprising:

converting, in an analog domain, between a radio frequency signal and an analog intermediate frequency signal;

converting between the analog intermediate frequency signal and corresponding digitized intermediate frequency signal data;

buffering the digitized intermediate frequency signal data in a buffer;

under control of a direct memory access controller in communication with a processor, transferring, in page multiples, pages of digitized IF signal data between the buffer and memory without interrupting the processor; and

processing the digitized intermediate frequency signal data in a computer program.