Communication device and method for reducing effects of noise introduction by synchronizing data transfer to a received signal

• US 5,838,741 A
• Filed: 02/10/1997
• Issued: 11/17/1998
• Est. Priority Date: 02/10/1997
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ansari, Zakir Hussain, Hayes, David Jeffrey, Mock, Von Alan, Eaton, Eric Thomas, Callaway, Edgar Herbert Jr.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Liu, Shuwang
• Application Number:
  US08/797,324
• Time in Patent Office: 645 Days
• Field of Search: 375/344, 375/347, 375/353, 375/376, 375/346, 375/342, 375/343, 375/345, 375/316, 455/260, 455/226.2, 455/265, 455/324, 340/825.44, 340/825.72
• US Class Current: 375/346
• CPC Class Codes: H03K 5/1252 Suppression or limitation of noise or interference specially adapted for transmission systems H04B15/00, H04L25/08
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04

Abstract

A communication device (100) having a receiver circuit (110), signal processor circuit (120), controller circuit (130), either embodied by integrated circuits or on a single integrated circuit. The transfer of signals between the circuits is timed so as to minimize the effects of noise introduced into any one of the circuits, particularly the receiver circuit (110). The center of a symbol of a received RF symbol is detected and, through hardware control or software control, the transfer of a data signal generated by the signal processor circuit (120), for example, is permitted to occur only during a period(s) of time determined to have minimal effects on the sampling of a symbol in a received signal by the receiver circuit (110).

Claims

1. A communication device comprising:

an antenna for detecting a radio frequency signal;

a receiver circuit coupled to the antenna for receiving the radio frequency signal and generating at an output a demodulated signal therefrom;

a signal processing circuit having an input coupled to the output of the receiver circuit for processing the demodulated signal to generate at an output a data signal;

a first electrical communication path coupling the output of the receiver circuit to the input of the signal processing circuit; and

a controller circuit coupled to the output of the signal processing circuit, the controller circuit generating a transfer control signal to control timing of transfer of signals between the receiver circuit, the signal processing circuit and the controller circuit, by;

determining when a predetermined portion of a symbol in the radio frequency signal is at an input to the receiver circuit;

initiating a time delay of a first predetermined period of time upon determining the predetermined portion of a symbol; and

generating the transfer control signal to enable transfer of the data signal for a second predetermined period of time beginning after the first predetermined period of time.

2. The communication device of claim 1, wherein the controller circuit generates the transfer control signal to control timing of transfer of the data signal from the signal processing circuit to the controller circuit such that the data signal is transferred to the controller circuit during a time window determined to minimize effects of noise introduced into the communication device.

3. The communication device of claim 1, wherein the controller circuit generates the transfer control signal to control timing of transfer of the data signal from the signal processing circuit to the controller circuit with respect to occurrence of symbols of the radio frequency signal.

4. The communication device of claim 1, wherein the controller circuit is programmed in the step of determining to generate a recovered data clock signal at an expected symbol rate of a signal to be received, and the step of initiating comprises generating a delayed data clock signal which is delayed by the first predetermined period of time from the recovered data clock signal, and the step of generating comprises generating the transfer control signal which is at a first value beginning at a negative-going edge of the delayed data clock signal to enable transfer of the data signal and is at a second value to disable transfer of the data signal.

5. The communication device of claim 1, wherein the signal processor circuit comprises a synchronizer circuit for sampling and synchronizing to the demodulated signal generated by the receiver circuit, the synchronizer circuit generating a noise inhibit signal having a first level when noise is determined to have a minimum effect on transfer of signals between circuits of the communication device to enable transfer of signals between circuits, and a second level when noise is determined to have a maximum effect on transfer of signals to thereby disable such transfer of signals.

6. The communication device of claim 1, wherein the receiver circuit, signal processing circuit and controller circuit are separate integrated circuit devices.

7. The communication device of claim 1, wherein the receiver circuit, signal processing circuit and controller circuit are integrated into a single integrated circuit.

8. The communication device of claim 1, wherein the controller circuit is programmed to generate the transfer control signal to account for multiple interference points of entry of the communication device, the transfer control signal comprising time periods determined to be suitable for transfer of signals between circuits of the communication device with respect to each interference point of entry and with respect to a center of a symbol of the radio frequency signal received by the receiver circuit.

9. The communication device of claim 1, and further comprising at least one peripheral circuit coupled to the signal processor circuit and the control circuit, wherein the control circuit controls the transfer of signals between the signal processor circuit and the at least one peripheral circuit so as to minimize effects of noise on the receiver circuit.

10. A method for controlling transfer of signals between circuits, including a receiver circuit that receives a radio frequency signal and generates a demodulated signal, a signal processing circuit that processes the demodulated signal and generates a data signal, and a controller circuit that processes the data signal, the method comprising steps of:

determining a time window when effects of noise introduced into the receiver circuit due to transfer of signals between circuits will be minimized, the step of determining further comprising the substeps of;

determining when a predetermined portion of a symbol in the radio frequency signal is received; and

initiating a time delay of a first predetermined period of time upon determining the predetermined portion of a symbol; and

generating a transfer control signal to enable transfer of information between the circuits during the time window, the step of generating further comprising the substep of;

generating the transfer control signal to enable transfer of the data signal for a second predetermined period of time beginning after the first predetermined period of time.

11. The method of claim 10, wherein the step of determining comprises determining time periods suitable for transfer of signals between circuits with respect to each interference point of entry and with respect to a center of a symbol of the radio frequency signal received by the receiver circuit.

12. The method of claim 10, wherein the step of determining comprises determining when the center of a symbol in the radio frequency signal is at an input to the receiver circuit.