Extended range concentric cell base station

• US 6,363,261 B1
• Filed: 08/31/1998
• Issued: 03/26/2002
• Est. Priority Date: 08/31/1998
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Raghavan, Ramabadran S.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US09/143,788
• Time in Patent Office: 1,303 Days
• Field of Search: 455/422, 455/423, 455/424, 455/434, 455/456, 455/561, 455/515, 455/334, 455/443-4, 370/350, 370/335, 370/337, 370/252, 375/150
• US Class Current: 455/561
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present invention is an extended range concentric cell base station and a method for extending a cell size or access range without incurring ASIC correlator re-design. This is accomplished with a concentric cell base station design that incorporates multiple timing protocols and search windows. The concentric base station has associated a micro cell and a macro cell, wherein the micro and macro cells use a same frequency band but different timing protocols and search windows that will cause signals transmitted by mobile-telephones within their respective cells to be received within the confines of at least one search window.

Claims

1. A method for detecting a mobile-telephone signal comprising the steps of:

transmitting a base station signal at a first frame boundary;

searching at the base station for a mobile-telephone signal using a first search window beginning at a second frame boundary and ending at a time p₁ after the second frame boundary, wherein p₁ represents a time interval corresponding to a bit limitation for a first correlator; and

searching at the base station for the mobile-telephone signal using a second search window beginning after the second frame boundary but no later than the time p₁ after the second frame boundary and ending at a time p₂ after the second search window began, wherein p₂ represents a time interval corresponding to a bit limitation for a second correlator.

2. The method of claim 1 further comprising the step of:

detecting the mobile-telephone signal using a correlator.

3. The method of claim 2, wherein the mobile-telephone signal is detected when a resulting signal of an incoming signal multiplied with a known code exceeds a threshold.

4. The method of claim 3, wherein the known code is a pseudo-random noise sequence.

5. The method of claim 1, wherein the first frame boundary and the second frame boundary are identical.

6. The method of claim 1, wherein the first frame boundary and the second frame boundary are not identical.

8. The method of claim 1, wherein the first correlator and second correlator are the same.

9. The method of claim 1, wherein the first correlator and second correlator are not the same.

7. A method for detecting a mobile-telephone signal comprising the steps of:

transmitting a base station signal at a first frame boundary;

searching at the base station for a mobile-telephone signal using a first search window beginning at a second frame boundary and ending at a time p₁ after the second frame boundary, wherein p₁represents a time interval corresponding to a bit limitation for a first correlator; and

searching at the base station for the mobile-telephone signal using a second search window beginning after the second frame boundary but no later than the time p₁ after the second frame boundary and ending at a time p₂ after the secone seach window began, wherein p₂ represents a time interval corresponding to a bit limitation for a second correlator, wherein the step of searching for the mobile-telephone signal using the second search window is performed only if the nobil-telephone signal is not detected by the step of searching for the mobile-telephone signal using the first search window.

10. A base station comprising:

a first radio for transmitting base station signals at a frame boundary, the first radio having a first correlator configured to search for mobile-telephone signal during a first time interval beginning at the frame boundary and ending a time p₁ after the frame boundary, wherein p₁ represents a time interval corresponding to a bit limitation for the first correlator; and

a second radio co-located with the first radio for transmitting base station signals at a time r relative to the frame boundary, the second radio having a second correlator configured to search for the mobile-telephone signal during a second time interval beginning after the frame boundary but to later than time p₁ after the frame boundary and ending at a time p₂ after the second time interval began, wherein p₂ represents a time interval corresponding to a bit limitation for the second correlator.

11. The base station of claim 10, wherein the first correlator detects the mobile-telephone signals when a resulting signal of an incoming signal multiplied with a known code exceeds a threshold value.

12. The base station of claim 10, wherein the second correlator detects the mobile-telephone signals when a resulting signal of an incoming signal multiplied with a known code exceeds a threshold value.

13. The base station of claim 10 further comprising:

a GPS receiver for receiving timing information for aligning the frame boundaries.