Method and apparatus in a wireless communication system for adding a second channel that overlaps a guard band used by a first channel

• US 6,154,500 A
• Filed: 05/20/1998
• Issued: 11/28/2000
• Est. Priority Date: 05/20/1998
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dorenbosch, Jheroen Pieter, Carsello, Stephen Rocco
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Ha, Dac V.
• Application Number:
  US09/083,250
• Time in Patent Office: 923 Days
• Field of Search: 375/259, 375/260, 375/261, 375/264, 375/377, 370/342, 370/343, 370/344
• US Class Current: 375/259
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2675 Pilot or known symbols
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems

Abstract

In a wireless communication system a first transmission (612, 614) is sent (802) over a first channel to a first receiver (122) that requires a transmission-free guard band (620) during a tuning period, and the first receiver accommodates a second transmission (616) sent concurrently with the first transmission on a second channel that overlaps with spectrum occupied by the guard band. During the tuning period, the system disallows the second transmission, and the first receiver adjusts (804) a pass band of a radio frequency (RF) filter (302) therein such that the pass band includes the guard band. Thereafter, the first receiver tunes (806) to the first channel. During a time other than the tuning period, the first receiver readjusts (810) the pass band of the RF filter such that the pass band excludes the guard band. After the tuning period, the system allows the second transmission to be sent (812).

Claims

1. A method in a wireless communication system for facilitating a sending of a first transmission over a first channel to a first receiver that requires a transmission-free guard band during a tuning period, and further for accommodating a second transmission on a second channel that overlaps with spectrum occupied by the guard band, the second transmission sent concurrently with the first transmission,

the method comprising, during the tuning period, the steps of:

disallowing the second transmission;

adjusting a pass band of a radio frequency (RF) filter in the first receiver such that the pass band includes the guard band; and

thereafter, tuning the first receiver to the first channel,

the method further comprising, during a time other than the tuning period, the steps of;

readjusting the pass band of the RF filter such that the pass band excludes the guard band; and

thereafter, allowing the second transmission.

2. The method of claim 1,

wherein the second transmission is intended for a second receiver, and

wherein the first transmission and the second transmission are synchronized with one another, and

wherein the method further comprises the step of synchronizing the second receiver to the second transmission by monitoring the first transmission during the tuning period.

3. The method of claim 1, further comprising the step of

sending a plurality of first transmissions over a plurality of first channels to a plurality of first receivers that require transmission-free guard bands during the tuning period, and

wherein the second transmission is intended for a second receiver, and

wherein the plurality of first transmissions and the second transmission are synchronized with one another, and

wherein the method further comprises the step of synchronizing the second receiver to the second transmission by monitoring one of the plurality of first transmissions during the tuning period.

4. The method of claim 1,

wherein the first transmission is a frequency shift keyed (FSK) transmission, and

wherein the second transmission is a quadrature amplitude modulated (QAM) transmission intended for a second receiver, and

wherein the method further comprises the step of sending a synchronization signal in the first transmission for synchronizing the first and second receivers.

5. The method of claim 1,

wherein the first receiver maintains a tuning error within a predetermined range, and

wherein the adjusting step comprises the step of widening the pass band to accommodate the predetermined range.

6. The method of claim 1,

wherein the second transmission is intended for a second receiver that can have a tuning error, and

wherein the method further comprises in the second receiver the step of monitoring the first transmission during the tuning period to minimize the tuning error.

7. The method of claim 1, further comprising the step of

sending a plurality of first transmissions over a plurality of first channels to a plurality of first receivers that require transmission-free guard bands during the tuning period, and

wherein the second transmission is intended for a second receiver that can have a tuning error, and

wherein the method further comprises in the second receiver the step of monitoring one of the plurality of first transmissions during the tuning period to minimize the tuning error.

8. A controller in a wireless communication system for sending a first transmission over a first channel to a first receiver that requires a transmission-free guard band during a tuning period, and further for accommodating a second transmission on a second channel that overlaps with spectrum occupied by the guard band, the second transmission sent concurrently with the first transmission, the controller comprising:

a network interface for receiving messages sent in the first and second transmissions;

a processing system coupled to the network interface for processing the messages;

and a base station interface coupled to the processing system for controlling a base station to generate the first and second transmissions,

wherein the processing system is programmed, during the tuning period, to;

disallow the second transmission; and

rely upon the first receiver to;

adjust a pass band of a radio frequency (RF) filter in the first receiver such that the pass band includes the guard band; and

thereafter, tune itself to the first channel, and

wherein the processing system is further programmed, during a time other than the tuning period, to;

rely upon the first receiver to readjust the pass band of the RF filter such that the pass band excludes the guard band; and

allow the second transmission.

9. The controller of claim 8,

wherein the processing system is further programmed to maintain synchronization between the first transmission and the second transmission.

10. The controller of claim 8,

wherein the first transmission is a frequency shift keyed (FSK) transmission, and

wherein the second transmission is a quadrature amplitude modulated (QAM) transmission intended for a second receiver, and

wherein the processing system is further programmed to send a synchronization signal in the first transmission for synchronizing the first and second receivers.

11. The controller of claim 8,

wherein the processing system is further programmed to send a plurality of first transmissions over a plurality of first channels to a plurality of first receivers that require transmission-free guard bands during the tuning period, and

wherein the plurality of first transmissions are frequency shift keyed (FSK) transmissions, and

wherein the second transmission is a quadrature amplitude modulated (QAM) transmission intended for a second receiver, and

wherein the processing system is further programmed to send a synchronization signal in the plurality of first transmissions for synchronizing the plurality of first receivers and the second receiver.

12. The controller of claim 8, further comprising first and second controllers,

wherein the first controller is arranged to control the first transmission, and

wherein the second controller is arranged to control the second transmission.

13. A receiver in a wireless communication system, the receiver for receiving a first transmission over a first channel, wherein the receiver requires a transmission-free guard band during a tuning period, the receiver further for accommodating a second transmission on a second channel that overlaps with spectrum occupied by the guard band, the second transmission sent concurrently with the first transmission from a controller, the receiver comprising:

a receiver element for receiving the first transmission, the receiver element comprising an adjustable radio frequency (RF) filter for controlling a pass band of the receiver element;

a processing system coupled to the receiver element for processing information sent in the first transmission; and

a user interface coupled to the processing system for interfacing with a user,

wherein the processing system is programmed, during the tuning period, to;

rely upon the controller to disallow the second transmission;

adjust the pass band of the RF filter such that the pass band includes the guard band; and

thereafter, tune the receiver to the first channel, and

wherein the processing system is further programmed, during a time other than the tuning period, to

readjust the pass band of the RF filter such that the pass band excludes the guard band, thereby enabling the receiver to receive the first transmission whether or not the second transmission is present.

14. The receiver of claim 13,

wherein the first transmission is a frequency shift keyed (FSK) transmission including a synchronization signal, and

wherein the second transmission is a quadrature amplitude modulated (QAM) transmission intended for a second receiver, and

wherein the processing system is further programmed to synchronize the receiver with the synchronization signal.

15. The receiver of claim 13,

wherein the receiver maintains a tuning error within a predetermined range, and

wherein the processing system is further programmed to widen the pass band to accommodate the predetermined range.

16. A receiver in a wireless communication system, the receiver for receiving a first transmission over one of at least one first channel also used by an additional receiving device that requires transmission-free guard bands during a tuning period, the receiver further for receiving a second transmission on a second channel that overlaps with spectrum occupied by one of the guard bands, the second transmission sent concurrently with the first transmission, the receiver comprising:

a receiver element for receiving the first and second transmissions;

a processing system coupled to the receiver element for processing information sent in the first and second transmissions; and

a user interface coupled to the processing system for interfacing with a user,

wherein the processing system is programmed, during the tuning period, to;

tune the receiver element to the one of the at least one first channel, and

minimize a tuning error of the receiver element by monitoring the first transmission, and

wherein the processing system is programmed, during a time other than the tuning period, to;

tune the receiver element to the second channel; and

process the information sent in the second transmission.

17. The receiver of claim 16,

wherein the receiver element and the processing system are arranged to cooperate to receive and decode the information sent in the first transmission as a frequency shift keyed (FSK) transmission, and to receive and decode the information sent in the second transmission as a quadrature amplitude modulated (QAM) transmission.

18. The receiver of claim 16,

wherein the receiver element comprises an adjustable radio frequency (RF) filter for controlling a pass band of the receiver element, and

wherein the processing system is further programmed to adjust the adjustable RF filter in accordance with a bandwidth of the first and second transmissions and further in accordance with a tuning error of the receiver element.

19. The receiver of claim 16,

wherein the processing system is further programmed, during the tuning period, to synchronize the receiver with a synchronization signal present in the first transmission.

20. The receiver of claim 16,

wherein the processing system is further programmed, after the tuning period, to synchronize the receiver with a synchronization signal present in the second transmission.