Method and apparatus for communicating a call

• US 6,426,980 B1
• Filed: 10/04/1999
• Issued: 07/30/2002
• Est. Priority Date: 10/04/1999
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gorday, Paul Edward, Leitch, Clifford Dana, Kuznicki, William Joseph, DʼAmico, Thomas Victor
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US09/411,107
• Time in Patent Office: 1,030 Days
• Field of Search: 375/260, 375/261, 375/295, 375/316, 375/298, 375/340, 714/762, 714/787, 714/761
• US Class Current: 375/295
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 5/12 the signals being represented by different phase modulations of a single carrier

Abstract

A wireless communication system (10) employing quadrature amplitude modulation techniques comprises a system controller (22), at least one radio frequency base transmitter (26), and at least one wireless communication device (35). The system controller (22) generates a downlink call (34) for transmission between the radio frequency base transmitter (26) and the wireless communication device (35). Multiplexing an I-channel bit stream (74) comprised of a first set of calls (70) interleaved together and a Q-channel bit stream (80) comprised of a second set of calls (76) interleaved together generates the downlink call (34). One wireless communication device demultiplexes the downlink call (34) and processes the I-channel bit stream (74). Another wireless communication device demultiplexes the downlink call (34) and processes the Q-channel bit stream (80).

Claims

1. In a wireless communication system having a system controller, a radio frequency base transmitter, and at least one wireless communication device, a method employing quadrature amplitude modulation for communicating a downlink call between the radio frequency base transmitter and the wireless communication device, the method comprising:

interleaving a first set of calls, and generating an I-channel bit stream comprised of the interleaved first set of calls;

interleaving a second set of calls, and generating a Q-channel bit stream comprised of the interleaved second set of calls;

generating the downlink call by modulating the I-channel bit stream onto an in-phase carrier component of the downlink call and modulating the Q-channel bit stream onto a quadrature phase carrier component of the downlink call.

2. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 1 wherein the generating of the downlink call further comprises:

converting the modulated I-channel bit stream and Q-channel bit stream into a complex symbol stream.

3. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 2, wherein the I-channel bit stream includes a first bit from a first call and the Q-channel bit stream includes a second bit from a second call, and further wherein the converting step comprises generating a symbol by pairing the first bit and the second bit.

4. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 1 wherein the interleaving of the first set of calls comprises:

interleaving the first set of calls into an I-channel interleaving block; and

generating the I-channel bit stream from the I-channel interleaving block.

5. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 1 wherein the interleaving of the first set of calls comprises:

interleaving the second set of calls into a Q-channel interleaving block; and

generating the Q-channel bit stream from the Q-channel interleaving block.

6. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 1 further comprising:

transmitting the downlink call from the radio frequency base transmitter to the wireless communication device; and

processing the downlink call within the wireless communication device.

7. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 6 whereby the processing step comprises:

receiving the downlink call; and

processing the I-channel bit stream to retrieve the first set of calls.

8. A method for communicating a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 6 whereby the processing step comprises:

receiving the downlink call; and

processing the Q-channel bit stream to retrieve the second set of calls.

9. In a wireless communication system employing quadrature amplitude modulation for communicating a downlink call between a radio frequency base transmitter and at least one wireless communication device, a system controller for controlling the communication of the downlink call comprising:

a first interleaver, having an input and an output, for interleaving a first set of calls and generating an I-channel bit stream comprised of the interleaved first set of calls;

a second interleaver, having an input and an output, for interleaving a second set of calls and generating a Q-channel bit stream comprised of the interleaved second set of calls; and

a multiplexer coupled to the output of the first interleaver and the output of the second interleaver for modulating the I-channel bit stream onto an in-phase carrier component of the downlink call and modulating the Q-channel bit stream onto a quadrature phase carrier component of the downlink call to generate the downlink call.

10. A system controller for controlling the communication of a downlink call between a radio frequency base transmitter and a wireless communication device as recited in claim 9 further comprising:

a channel manager coupled to the input of the first interleaver and the input of the second interleaver for assigning a first set of calls to the first interleaver and a second set of calls to the second interleaver.

11. In a wireless communication system employing quadrature amplitude modulation for communicating a downlink call between a radio frequency base transmitter and at least one wireless communication device, a system controller for controlling the communication of the downlink call comprising:

a message processor for processing a plurality of calls;

a channel manager coupled to the message processor, a first interleaver, and a second interleaver, for assigning a first set of calls to the first interleaver and a second set of calls to the second interleaver;

a first interleaver coupled to the channel manager, for interleaving the first set of calls received from the channel manager, and generating an I-channel bit stream comprised of the interleaved first set of calls;

a second interleaver coupled to the channel manager, for interleaving the second set of calls received from the channel manager, and generating a Q-channel bit stream comprised of the interleaved second set of calls;

a multiplexer for modulating the I-channel bit stream onto an in-phase carrier component of a multiplexed signal and modulating the Q-channel bit stream onto a quadrature phase carrier component of the multiplexed signal to generate the multiplexed signal; and

a communication interface coupled to the multiplexer for receiving the multiplexed signal and generating the downlink call.

12. In a wireless communication system having at least one radio frequency base transmitter and employing quadrature amplitude modulation, a wireless communication device for receiving a downlink call from the radio frequency base transmitter, the wireless communication device comprising:

a receiver for receiving the downlink call including an I-channel bit stream modulated onto an in-phase carrier component of the downlink call and a Q-channel bit stream modulated onto a quadrature phase carrier component of the downlink call, wherein;

the I-channel bit stream comprises an interleaved first set of calls, and

the Q-channel bit stream comprises an interleaved second set of calls;

a call manager coupled to the receiver for routing the downlink call to an I-channel processor when the first set of calls includes a call destined for the wireless communication device; and

the I-channel processor coupled to the call manager for processing the I-channel bit stream of the downlink call received from the call manager.

13. A wireless communication device for receiving a downlink call from a radio frequency base transmitter as recited in claim 12 wherein the I-channel processor comprises:

a first demodulator for demodulating the I-channel bit stream, and generating a first demodulated bit stream; and

an I-channel deinterleaver coupled to the first demodulator, for receiving and deinterleaving the first demodulated bit stream.

14. A wireless communication device for receiving a downlink call from a radio frequency base transmitter as recited in claim 13, wherein the first demodulator comprises a variable rate QAM demodulator for extracting a QAM. modulation level from the I-channel bit stream and demodulating the I-channel bit stream according to the extracted QAM modulation level.

15. A wireless communication device for receiving a downlink call from a radio frequency base transmitter as recited in claim 12 further comprising:

a Q-channel processor coupled to the call manager for processing the Q-channel bit stream of the downlink call received from the call manager, wherein the call manager routes the downlink call to the Q-channel processor when the second set of calls includes a call destined for the wireless communication device.

16. A wireless communication device for receiving a downlink call from a radio frequency base transmitter as recited in claim 15 wherein the Q-channel processor comprises:

a second demodulator for demodulating the Q-channel bit stream, and generating a second demodulated bit stream; and

a Q-channel deinterleaver coupled to the second demodulator, for receiving and deinterleaving the second demodulated bit stream.

17. A wireless communication device for receiving a downlink call from a radio frequency base transmitter as recited in claim 16, wherein the second demodulator comprises a variable rate QAM demodulator for extracting a QAM modulation level from the Q-channel bit stream and demodulating the Q-channel bit stream according to the extracted QAM modulation level.

18. A wireless communication device as recited in claim 12 further comprising:

a QAM modulator for generating a QAM call; and

a device transmitter coupled to the QAM modulator for transmitting the uplink call.

19. In a wireless communication device, a method for receiving a first set of calls from a wireless communication system employing QAM modulation techniques, the method comprising:

receiving a downlink call including an I-channel bit stream modulated onto an in-phase carrier component of the downlink call and a Q-channel bit stream modulated onto a quadrature phase carrier component of the downlink call; and

processing the I-channel bit stream of the downlink call to retrieve the first set of calls when the first set of calls includes a call destined for the wireless communication device.

20. A method as recited in claim 19 wherein the processing step comprises:

demodulating the I-channel bit stream, and generating a first demodulated bit stream; and

deinterleaving the first demodulated bit stream, and retrieving the first set of calls.

21. A method as recited in claim 20 wherein the demodulating step comprises extracting the QAM modulation level from the I-channel bit stream, and demodulating the I-channel bit stream according to the QAM modulation level.

22. A method as recited in claim 21 further comprising:

identifying that the first set of calls are contained within the I-channel bit stream before the processing step.

23. In a wireless communication device, a method for receiving a second set of calls from a wireless communication system employing QAM modulation techniques, the method comprising:

receiving a downlink call including an I-channel bit stream modulated onto an in-phase carrier component of the downlink call and a Q-channel bit stream modulated onto a quadrature phase carrier component of the downlink call; and

processing the Q-channel bit stream of the downlink call to retrieve the second set of calls when the second set of calls includes a call destined for the wireless communication device.

24. A method as recited in claim 23 wherein the processing step comprises:

demodulating the Q-channel bit stream, and generating a second demodulated bit stream; and

deinterleaving the second demodulated bit stream, and retrieving the second set of calls.

25. A method as recited in claim 24 wherein the demodulating step comprises:

extracting the QAM modulation level from the Q-channel bit stream, and demodulating the Q-channel bit stream according to the QAM modulation level.

26. A method as recited in claim 23 further comprising:

identifying that the second set of calls are contained within the Q-channel bit stream before the processing step.

27. In a wireless communication device, a method for receiving a first set of calls and a second set of calls from a wireless communication system employing QAM modulation techniques, the method comprising:

receiving a downlink call including an I-channel bit stream modulated onto an in-phase carrier component of the downlink call and a Q-channel bit stream modulated onto a quadrature phase carrier component of the downlink call;

identifying that the first set of calls are contained within the I-channel bit stream;

identifying that the second set of calls are contained within the Q-channel bit stream;

processing the I-channel bit stream of the downlink call to retrieve the first set of calls; and

processing the Q-channel bit stream of the downlink call to retrieve the second set of calls.