Patent Application
20080056206
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in a method and apparatus for managing power consumption in a communication system. Accordingly, the communication system has been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
While the specification concludes with claims defining the features of the embodiments of the invention that are regarded as novel, it is believed that the method, system, and other embodiments will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward.
As required, detailed embodiments of the present method and system are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the embodiments of the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the embodiment herein.
The terms “a” or “an,” as used herein, are defined as one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. The term “suppressing” can be defined as reducing or removing, either partially or completely. The term “processor” can be defined as any number of suitable processors, controllers, units, or the like that carry out a pre-programmed or programmed set of instructions.
The terms “program,” “software application,” “routine” and the like as used herein, are defined as a sequence of instructions designed for execution on a computer system. A program, computer program, or software application may include a subroutine, a function, a procedure, an object method, an object implementation, an executable application, an applet, a servlet, a source code, an object code, a shared library/dynamic load library and/or other sequence of instructions designed for execution on a computer system.
In this document, relational terms such as first and second and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
Briefly, in accordance with the present invention, the error mitigated signal generated at base unit 104 is also received back at the originating subscriber unit 102. The originating subscriber unit 102 then performs a comparison of the repeated signal to a plurality of previously calculated and stored voice frames. The result of the comparison determines whether a transmit power control adjustment is made within the subscriber unit 102. By utilizing the repeated signal, the originating subscriber unit 102 is able to adjust itself quickly in response to changes in environmental conditions. Basically, the originating subscriber unit 102 is “eavesdropping” or “listening in” on the error information being relayed to the one or more final intended subscriber units 106.
To further elaborate, the power control of the present invention is accomplished by having the subscriber unit 102 transmit a signal including vocoder voices frames to the base unit 104, and then the base unit 104 repeats the signal, including error information from the voice frames for one or more subscriber units 106, while the original transmitting unit 102 monitors the amount of error mitigation in the repeated signal. The voice frames having error information are also referred to as error mitigated voice frames. In accordance with the present invention, the subscriber unit 102 compares the received error mitigated voice frames to one or more voice frame conditions. These voice frame conditions may include, for example, calculated frames, delayed frames and muted signal patterns. Calculated frames are preferably derived from previous voice transmitted frames. Delayed frames are those frames that were last transmitted and now stored. The muted signal pattern is pre-stored. Based on the comparison of the received error mitigated voice frames to voice frame conditions, the subscriber unit 102 automatically adjusts its transmit power level.
The base unit 104 (of
As previously mentioned, the communication protocol governing communication system 100 may be a full duplex or half duplex protocol. For full-duplex operation, both transmit and receive signals can occur on simultaneously. For half-duplex operation, transmit and receive signals occur on alternate time slots. For full-duplex protocols, the repetition of the error mitigated voice frames from the base 104 to the final recipient 106 (also listened to by the originating subscriber unit 102) can occur at any time slot while for half-duplex operation the repetition occurs on alternate time slots. Thus, the power management control of the present invention applies to both full-duplex and half-duplex systems as well as combination systems having half-duplex modes and full-duplex modes of operation.
In accordance with the present invention, subscriber unit 102 generates vocoder voice frames 305 at vocoder 304 and forwards these frames to FEC encoder 314. FEC encoded vocoder voice frames 307 are transmitted via transmitter 210 and antenna 214 to the base unit 104. Base unit 104 receives the incoming RF signal at receiver 110 and determines the error of the FEC vocoder voice frames using vocoder FEC decoding 318 in a manner known in the art. Depending on the error rate, the vocoder voice frames are modified as necessary to provide error mitigated voice frames in a manner consistent with methods known in the art. The error mitigated voice frames are repeated via the base unit's transmitter 112 to the subscriber unit 106. In accordance with the present invention, the subscriber unit 102 also receives the repeated error mitigated voice frames at receiver 212. The error mitigated frames are decoded within DSP 206 utilizing FEC decoder 316. The decoded error mitigated voice frames generated by FEC decoder 316 are compared, using a comparator or the like, 302 to pre-stored and pre-calculated voice frame conditions. For this example the conditions are: the original vocoder encoder frames 305, calculated smoothed frames 309, delayed frames 311 and the stored muted frame 313.
The voice frame conditions are pre-calculated and pre-stored patterns that provide references with which to compare at 302 the received repeated error mitigated voice frames 317. In accordance with this embodiment, the voice frame conditions within DSP 206 are generated by taking the output of the vocoder encoder 304 in the transmit path and performing such functions as: calculating a smoothed representation of the frames at 308 and storing previously transmitted frames to create “delayed” frames” at 310. Muted frames, including frames having comfort noise inserted thereon (CNI muted frames), can be stored at 312. In accordance with this embodiment, the FEC decoded signal 317 is compared at 302 to the original vocoder frames 305, calculated frames 309, delayed frames 311 and muted frames 313 to determine whether the frame patterns match. If the comparison at 302 results in a match (or failure to match for some conditions) then a power adjustment is made via transmit power control 208.
If the received error mitigated frame pattern 317 matches delayed frame pattern 311, then no action is taken. If the received error mitigated frame pattern 317 fails to match the delayed frame pattern 311, then transmit power control 208 is increased by a first predetermined level at transmitter 210. If the received error mitigated frame pattern 317 matches the smoothed (calculated) pattern 309, then transmit power control 208 is increased by a second predetermined level at transmitter 210. If the received error mitigated frame 317 matches the muted frame pattern 313, then transmit power is increased by a third predetermined level—this third predetermined level is preferably higher than the first or second power level increases since more power is typically required to overcome the muted condition. At most, only one condition is met for a given frame. The amount of power level increase set for each condition can be determined and adjusted based on system parameters relating to the level of errors in the error mitigated frames.
Again power levels need not be adjusted if the received error mitigated frame 317 matches delayed frame 311, this being an indication that power levels are already appropriately set. Power adjustments need only occur when the error in the repeated error mitigated voice frames indicate that an adjustment is needed. The power level of the adjustment is based on the type of voice frame condition present—the muted condition preferably initiating a higher power increase than the calculated condition.
The power adjustment of the present invention allows for the originating subscriber unit to give itself a “power boost” if it determines there were too many errors in its originally transmitted signal received at base unit 104. The originating subscriber unit 102 is thus able to do a self-assessment based on the error mitigated signal repeated back from the base unit 104. This self-assessment is made without changes to the infrastructure of the system.
The error mitigated voice frames received by the originating portable communication device at 412 are FEC decoded at 414 to validate the received frames. This step ensures that only those error mitigated frames from base unit 104 having an acceptably small number of errors are used so that the power adjustment decision is made with a high degree of confidence. The FEC decoded frames are compared to previously calculated and stored vocoder frames at 416, and the portable communication device's transmit power is adjusted, if needed, at step 418 based on the approximation of the error rate as determined by matching or mismatching with the voice frame conditions.
Steps 402-410 and 420 are performed using well established techniques. Step 412-418 provide the portable communication device with the ability to automatically adjust its own power based on an error estimation from repeated vocoder voice frames. The ability of the portable subscriber to automatically adjust its own power based on an error estimation from repeated vocoder voice frames allows for an automatic power control technique that provides effective power control at the portable subscriber without changing the system infrastructure. Imperfect signal quality predictions at the base station or rapid changes in signal conditions can now be quickly overcome. Because an incorrect power level can be quickly corrected, a greater difference in the minimum to maximum power can be used which allows more power levels to be included within the subscriber. By increasing the number of available power levels, the battery life of the portable subscriber is increased. Furthermore, the use of estimation for the received error rate is significant in that the outbound bandwidth need not be increased. In other words, no “extra” information is needed in the reverse channel.
In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
