Method for bandwidth efficient multiple access wireless communication

• US 6,219,341 B1
• Filed: 03/18/1998
• Issued: 04/17/2001
• Est. Priority Date: 03/20/1997
• Status: Expired due to Fees

• Current Assignee: University Technology Corporation
• Original Assignee: University Technology Corporation
• Inventors: Varanasi, Mahesh K.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US09/040,783
• Time in Patent Office: 1,126 Days
• Field of Search: 370/252, 370/254, 370/251, 370/468, 370/535, 370/537, 370/319, 370/320, 370/321, 370/318, 370/317, 370/311, 370/332, 370/333, 370/335, 370/336, 370/337, 370/341, 370/347, 370/350, 370/441, 370/442, 370/310, 370/314, 370/219, 370/324, 370/326, 370/329, 370/376, 370/342-344, 370/480, 370/477, 455/38.3, 375/130
• US Class Current: 370/252
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers

Abstract

A method for wireless communication utilizes available channel bandwidth when multiplexing a plurality of user signals over a communication channel. The method utilizes signal power characteristics as a signature to multiplex and de-multiplex the plurality of signals applied to the communication channel. Many wireless communication applications are required to utilize a limited, assigned frequency range. Modulation of digital information in such a limited bandwidth is a critical factor in determining the data transferred through the wireless communication channel. The present invention provides for multiplexing of a plurality of digital data sequences over a wireless communication channel having a fixed frequency range. The method provides for a base station which dynamically assigns signaling power parameters to each remote device which is optimally bandwidth-efficient for present signal traffic loads and for present received power conditions. Depending upon a number of factors, the method improves channel bandwidth utilization by factors of two to three over presently known methods. The communication method may be applied to many communication applications wherein a plurality of diverse user signals are multiplexed onto a single communication channel. Exemplary of such applications are wireless voice communication, e.g. digital cellular telephony and wireless data communications, e.g. wireless computer networking.

Claims

1. A method for improving channel bandwidth utilization in a communication system, the method comprising the steps of:

providing an available communication channel;

evaluating available channel bandwidth for a plurality of signals applied to the available communication channel;

determining signal power characteristics of the plurality of signals;

defining a plurality of signature waveforms;

dynamically allocating the signature waveforms to a plurality of transmitters; and

multiplexing the plurality of signals onto the communication channel based on the plurality of signature waveforms.

2. The method of claim 1 wherein the plurality of signals are digital data sequences.

3. The method of claim 1 wherein the available channel has a fixed frequency range.

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

assigning signaling power parameters to each receiving device.

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

designing the signature waveforms for each receiving device.

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

designing the signature waveforms to meet receiver performance specifications for each user.

7. The method of claim 1 wherein the signature waveforms are re-designed based on changes in traffic conditions in the communication channel.

8. The method of claim 1 wherein the signature waveforms are re-designed based on received power levels.

9. The method of claim 1 wherein the signature waveforms are re-designed based on the number of transmitters.

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

using extra received power to assign signals with smaller bandwidths.

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

increasing the number of users by using extra received power to assign signals with smaller bandwidths.

12. A method for improving channel bandwidth utilization in a communication system, the method comprising the steps of:

providing an available communication channel;

evaluating available channel bandwidth for a plurality signals applied to the available communication channel;

determining signal power characteristics of the plurality of signals;

defining a plurality of signature waveforms;

multiplexing the plurality of signals onto the communication channel based on the plurality of signature waveforms; and

redesigning the plurality of signature waveforms based on changes in traffic conditions in the communication channel.