Before the ITU-induced deal between QCOM and ERICY in early 1999, QCOM declared that there was no way to design around its CDMA patents in rake receiver, soft hand-off, and power control.
It is well known that Price and Green invented the basic or fundamental or pioneering rake receiver technique in 1958 so QCOM's rake receiver patent can be seen as a highly innovative implementation patent at best, and open to the use of near-equivalent inventions.
It is also well known that ATT (Bell Labs) invented the basic or fundamental or pioneering handoff technique in 1972 so QCOM's soft handoff claim can again be seen as a highly innovative implementation patent at best, and open to near-equivalent inventions.
Below is a patent that provides a sketchy history of power control in spread spectrum systems which have been used extensively in the military. This patent is part of Golden Bridge's work on a proprietary 2-stage match filter technology that improves on the correlator bank designs used by QCOM. Note that MIT invented the basic or fundamental or pioneering match filter patent in the forties.
The relevant art section of the patent provides a brief history and of power control and describes the line of work by Qualcomm, Interdigital and Sony, each of which passed the novelty threshold for a patent and at the very least represents an independent approach to the power control problem. It doesn't necessarily mean that just because one implementation made it to the market first (CDMAOne), it will automatically become part of the next-gen standard especially when the proprietor of the current implementation of CDMA power control has been excluded from the 3GPP where the issue of basic and implementation patents for hybrid TDMA/CDMA networks will be handled in the years to come.
Patent Number 5,963,583
Fuzzy-logic spread-spectrum adaptive power control
164.195.100.11;
DESCRIPTION OF THE RELEVANT ART
The need for a means of controlling the power from remote users, simultaneously transmitting to and being received at a common base station, is well known and documented in the literature. As an example, consider the paper by Ormondroyd entitled, POWER CONTROL FOR SPREAD-SPECTRUM SYSTEMS published in April 1982 from the Conference on Communications Equipment and Systems in the United Kingdom and associated with the IEEE Communications Society (USA). In suggesting a particular power control solution, Ormondroyd references five additional papers dating back to 1979 which also describe the need for and means of effecting power control.
In recent times, several patents have been issued to inventors who have demonstrated their ingenuity by preparing algorithms which they employ to implement the power control required. These patents include:
[Interdigital]
U.S. Pat. No. 5,093,840, entitled ADAPTIVE POWER CONTROL FOR A SPREAD SPECTRUM TRANSMITTER and incorporated herein by reference, issued to Schilling on Mar. 3, 1992 and describes an apparatus for adaptive-power control (APC) of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation......
[Qualcomm]
U.S. Pat. No. 5,257,283, entitled SPREAD SPECTRUM TRANSMITTER POWER CONTROL METHOD AND SYSTEM and incorporated herein by reference, issued to Gilhousen et al., on Oct. 26, 1993 and discloses a power control system for a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell site using code division multiple access spread-spectrum communications signals.......
[Interdigital]
U.S. Pat. No. 5,299,226, entitled ADAPTIVE POWER CONTROL FOR A SPREAD SPECTRUM COMMUNICATIONS SYSTEM AND METHOD and incorporated herein by reference, issued to Schilling on Mar. 29, 1994, and discloses an adaptive power control method and apparatus for spread-spectrum communications, for use with a mobile station operating in a cellular communications network..........
[Sony]
U.S. Pat. No. 5,386,588, entitled TRANSMISSION POWER CONTROL OF MOBILE RADIOTELEPHONE STATION IN RESPONSE TO BASE STATION CONTROL SIGNAL WHERE BASE STATION DATA IS COLLECTED BY THE MOBILE RADIOTELEPHONE STATION and incorporated herein by reference, issued to Yasuda on Jan. 31, 1995, and discloses transmission power control of a mobile radiotelephone station in which radio communication channels, including control channels and a plurality of communication channels, are set between a plurality of base stations and a plurality of mobile stations within radio zones of the base stations..........
In the foregoing patent disclosures, control signals are sent for determining thresholds based on the signal intensity or power of a received spread-spectrum signal. The prior art does not teach measuring the signal power level of a received spread spectrum signal along with-the noise level within the same frequency band and within approximately the same time, for determining a signal-to-noise ratio (SNR). More particularly, these prior art patents compare a received level to a predetermined threshold and increase or decrease power accordingly. They do not teach measuring signal-to-noise ratio at the despreader, while attempting to bound the variation of the signal-to-noise ratio using a state diagram.
Further, the prior art patents do not teach the use of a state diagram for a fuzzy-logic solution to the problem of determining or adjusting the power level in response to the requirements of the environment. For example, in a typical mobile environment, a remote unit might pass through a geographical area, such as between two buildings, and encounter substantial fading. Absent significant adjustment in the power level, such fading could result in signal loss. The foregoing disclosures do not address an adaptive method or a method using artificial intelligence for adjusting the power level of the remote unit to offset the fading process. |
