Patent Abstract:
A base station for use in a wireless communications system is disclosed, including transceiver circuitry for transmitting and receiving with at least one mobile device over at least one communications channel. Polarization control logic is included for controlling a polarization of signals transmitted over the at least one communications channel. The polarization control logic adjusts a polarization of the signal transmitted on the at least one communications channel responsive to at least one parameter received from the mobile device relating to a quality of signal received on the at least one communications channel.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/543,233, filed on Jul. 6, 2012, entitled POLARIZATION CONTROL FOR CELL TELECOMMUNICATION SYSTEM, now U.S. Pat. No. 8,306,479, issued on Nov. 6, 2012, the specification of which is incorporated herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates in general to cellular telecommunication systems and, more particularly, to the method and apparatus for controlling the power level translated between the base station and a mobile unit. 
     BACKGROUND 
     Power control (PC) is an essential function of cellular telephone systems such as CDMA systems and WCDMA systems, as well as follow on systems thereto. It is important that the power transmitted from a base station (BS) to a mobile unit (MU) be closely controlled such that it is sufficiently high enough to ensure that the required communications and performance is achieved. This is also the case with respect to power transmitted from the MU to the BS. If more power is transmitted than is required, the MU, for example, will be required to utilize more of its battery power. The BS, although not being powered by battery, does have overall power requirements that need to be met as well. Thus, by reducing the amount of total power that is required to be transmitted to the maximum number of mobile units that could possibly be interfaced with the BS, a more efficient system could be utilized with optimized power supplies, etc. 
     Power control is facilitated utilizing only the traffic and access channels. The power levels transmitted from MUs to their BSs are very closely controlled, typically utilizing multiple control loops to ensure that just enough, but not too much, power is transmitted. One loop is utilized for open loop control and it is based on the level of power received over the total physical channel bandwidth. A second loop is comprised of a closed loop which utilizes measurements of power on reverse traffic channels to determine if the reverse-link is approximately at the level required. If it is not, a one-bit control message is sent out on the forward traffic channel to adjust the power of a particular link. A third loop can be utilized, usually called the outer loop, which appraises the overall performance of the closed loop using the reverse-link frame quality statistics. Internally, the parameters that are examined are typically such things as the Signal-to-Interference Ratio (SIR) and the bit error rate (BER). 
     One problem that exists with respect to a cellular telephone system which has a plurality of MUs disposed in the proximity to a particular BS is that the MUs can migrate into different microenvironments. For example, two MUs can be separated by a distance of 10 feet and be in a completely different environment due to the surrounding features of that environment. For example, one person may be outside of a building and the other person may be 10 feet away on the inside of the building looking out of a window. The communication properties between those two MUs are significantly different. This can be further exacerbated in a CDMA system wherein both MUs receive on substantially the same frequency utilizing only Welch codes to distinguish two people talking at the same time. This is facilitated by controlling the power on a per user basis. When an individual steps inside of a building the attenuation caused by the building will be compensated for by the MU requesting higher power to be transmitted from the BS and for the BS requesting higher power to be transmitted from the MU. This is fairly conventional. 
     One other factor with respect to these microenvironments is that the characteristics of the electromagnetic wave are varied as a result of the surrounding environment. Some of these characteristics are due to reflections which can change the polarization. For example, if a signal is reflected from a building, polarization could be rotated from a conventional vertical polarization to lead or lag that polarization. Since the handset corresponding to the MU is typically on the average expecting vertical polarization, this will result in some attenuation which will require a power increase in the overall band of interest in order to gain acceptable communications performance. This is also the case when entering the building, as the building itself will constitute a phase shifter. This is in addition to the attenuation of the building itself. The only solution at the present time is to utilize the power control features of the cellular communication system to facilitate the change. 
     SUMMARY 
     The present invention disclosed and claimed herein comprises, in one aspect thereof, a base station for use in a wireless communications system, including transceiver circuitry for transmitting and receiving with at least one mobile device over at least one communications channel. Polarization control logic is included for controlling a polarization of signals transmitted over the at least one communications channel. the polarization control logic adjusts a polarization of the signal transmitted on the at least one communications channel responsive to at least one parameter received from the mobile device relating to a quality of signal received on the at least one communications channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which: 
         FIG. 1  illustrates a diagrammatic view of a base station and multiple buildings in the locale of a particular base station; 
         FIG. 2  illustrates a diagrammatic view of a transmission to a mobile unit within a building; 
         FIG. 2   a  illustrates the detail of the change in transmission medium between the inside and the outside of a building; 
         FIG. 3  illustrates different polarization schemes for transmission through a building; 
         FIG. 4  illustrates a diagrammatic view of phase control for a base station antenna; 
         FIG. 5  illustrates a diagrammatic view of the control loop for power control in a WCDMA system; 
         FIG. 6  illustrates a plot of the polarization phase versus the Bit Error Rate; 
         FIG. 7  illustrates a flow chart for the overall operation of setting either the power or the phase control; 
         FIG. 7   a  illustrates a flow chart for the operation at the base station to change the phase of the polarization; 
         FIG. 8  illustrates a flow chart for one scenario wherein the power control precedes the phase control and the phase control only occurs within a valid time window; 
         FIG. 9  illustrates a flow chart wherein the phase control is only performed during an active link; 
         FIG. 10  illustrates a diagrammatic view of a near/far link wherein two mobile units share a common frequency; 
         FIG. 11  illustrates a diagrammatic view of a clustering algorithm; 
         FIG. 12  illustrates a flow chart depicting the operation of aggregating a plurality of mobile units and determining the setting of the polarization of the antenna based upon statistics from the plurality; and 
         FIG. 13  illustrates a simplified diagrammatic view of the control aspect of setting the polarization on either end of the communication link. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a polarization control for cell telecommunication system are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments. 
     Referring now to  FIG. 1 , there is illustrated a diagrammatic perspective view of a base station transmitting within a locale occupied by multiple buildings. The base station is illustrated by a tower  102  having an antenna  104  associated therewith. The antenna  104  is operable to transmit signals on various frequencies with various modulations. There are multiple cellular telephone schemes such as CDMA, WCDMA, GSM, UTS, etc. that can be utilized, depending upon the system for which the base station is configured. In any event, no matter what system is utilized, power is still required to be transmitted on a particular frequency at a particular level. Typically, when the signal falls below a certain level such as −106 dBm, a particular mobile unit will not be able to receive the signal, as the receiver associated therewith has a lower limit of receive sensitivity. Thus, it is important that the transmitter at the base station be able to transmit sufficient power to reach the periphery of the outer region or limits of the base station at that level. Of course, when a mobile unit is closer, the power must be adjusted downward. Further, it can be seen that, depending upon the microenvironments that exist in various portions of the base station locale, all or a portion of the signal energy can be attenuated or reflected. 
     In  FIG. 1 , there are illustrated two buildings  106  and  108 . A signal that is transmitted from the antenna on the Base Station is transmitted in an omnidirectional manner such that it is transmitted in all directions at once. Therefore, a transmitted signal will be directed toward building  106 , as seen by transmission path  110  which is reflected along a path  112 . Similarly, a signal is transmitted along a path  114  and reflected off of building  108  to provide a signal on a reflective path  114 . If there were a mobile unit in the region of both of the reflective waves, it would also receive a direct transmitted signal from the antenna  104  and must be able to distinguish among these different signals. 
     The transmitted wave from the antenna  104  will have a set of electromagnetic properties. These properties will include the power of the electromagnetic wave and the polarization of an electromagnetic wave, i.e., the orientation thereof, and the phase thereof. In an ideal world, with no buildings in the line of sight and no environmental impediments, a mobile unit will always be within the line of sight of a Base Station and will receive the signal with substantially no interference. There will be no “ghosting” that will result in multiple signals at the same frequency for the same modulation directed to the same mobile unit that are reflected from different objects. However, in a real world environment, not only will reflected waves be received from multiple other objects, but the transmitted signal that is received will be received with different electromagnetic properties due to the reflections thereof which can change the properties. 
     Referring now to  FIG. 2 , there is illustrated a diagrammatic view of a mobile unit  202  disposed within the interior of a building  204 . A transmitter  206  is operable to transmit a signal along a transmit path  208  to the building  204 . When it arrives at the boundary of a building between the base station transmitter  206  and the mobile unit  202 , two things will happen. First, the transmitted signal will encounter a change in transmission medium. If the mobile unit were disposed on the opposite side of a glass window, for example, the transmission medium would go from air to glass to air. At this transmission medium boundary, the transmitted signal would be divided into a transmitted portion  210  and a reflected portion  212  due the different properties at the boundary. The transmitted portion  210  will have the electromagnetic properties thereof changed as a result of the transmitted signal along path  208  encountering the transmission medium boundary. One change that occurs is that the polarization may vary. Typically, the polarization for a cellular system is vertical linear polarization. The reason for utilizing vertical linear polarization is to better cover ground based mobile units. As compared to horizontal polarization which provides for better coverage of line of sight receiving units on roof tops, i.e., television based signals, the vertical polarization covers the ground based units more completely. As a receiver is moved closer to the earth for horizontal polarization, the signal is attenuated, which is the opposite for vertical polarization. However, it should be understood that the mobile unit is designed to operate in a communication system wherein the antenna utilizes vertical polarization. Even though the polarization may be shifted to either lead or lag the nominal vertical polarization, on the average, the mobile unit is designed to provide adequate performance for substantially all orientations. Even the antenna designed for the orientation of a mobile unit when utilizing a conversation mode is typically designed such that it will be oriented with respect to the vertically polarized transmitting antenna during a normal call assuming an individual will always hold it the same way. However, if the mobile unit or phone is rotated such that attenuation does occur due to a shift in polarization, this will be compensated for in the conventional prior art system by adjusting the power level through the power control portion of the system. This could result in additional power being transmitted from the mobile unit or additional power being transmitted from the base station or both. 
     This polarization aspect is illustrated in  FIG. 2   a  wherein the transmitted signal  208  is transmitted through a wall  214  with the original polarization being vertical, as illustrated by a vertical arrow  216 . Once passing through the wall  214 , the transmitted path  210  has a polarization  218  that leads the vertical polarization  216 , i.e., it is rotated in phase. This will be received at the mobile unit  202  with slightly attenuated properties. This is due to the fact that the electromagnetic properties of the transmitted signals have been changed and, when the signal arrives at the receiving antenna on the mobile unit  202 , the change in those electromagnetic properties result in less than optimum reception at the receiving antenna. The receiver in the mobile unit  202  does not have the sophistication to make a determination that the electromagnetic properties have been altered; rather, all that the receiver in the mobile unit  202  can determine is signal strength. Typically, the antenna will feed an input band pass filter that will pass frequencies within the pass band of that filter, which will then be fed to a low noise amplifier and then processed to a receive string. Signal strength can be detected and measured above a predetermined level to make sure that at least a moderate level of signal power has been received. Thereafter, the received demodulated signal can be examined to determine if there were any errors. Typically, one can look at error rates such as the SIR and the BER to determine if data has been correctly received. If the error rate is too high, the assumption is made that there is an issue with respect to power and some action is taken to increase the transmit power along the path  210 . This error rate can be due to attenuation, phase shift, collision or any other reason. The simple fact is that current systems merely attempt to solve error rates by increasing power. This, of course, causes other problems with respect to adjacent channels but telecommunication protocols such as CDMA, GSM, etc. allow for power control on a per user basis. 
     As will be described herein below, rather than utilize the power control features of the various telecommunications systems or telecommunication protocols, the present disclosed embodiments attempt to correct for changes in the electromagnetic properties of the transmit signal. If the error rates can be improved by altering the transmission properties of the transmitted signal both to the mobile unit  202  and to the base station from the mobile unit  202 , then additional power is not required. (Although the embodiment of  FIG. 2  and  FIG. 2   a  only discuss transmitted power from the base station to the mobile unit, it should be understood that there is a return link from the mobile unit to the base station and electromagnetic properties of such a signal will vary as various transmission boundaries with respect to medium are encountered.) The change in these properties is facilitated by changing the way in which the antenna can transmit. As noted herein above, the base station will typically utilize a vertical linear polarization. By changing the polarization of the transmitted signal at the antenna through phase control, the polarization can be rotated at the antenna itself to actually adjust the polarization of the received signal at the receive antenna to match the characteristics of the receive antenna. If, for example, the polarization at the mobile unit leads the polarization at the antenna at the base station by 45°, for example, then it is only necessary to rotate the phase at the antenna to lag the vertical polarization by 45°. This will compensate for the polarization shift along the transmission path and, therefore, improve the error rates and the reception at the receiver in the mobile unit  202 . 
     Referring now to  FIG. 3 , there is illustrated a diagrammatic view of various polarization patterns and the transmission properties with respect thereto. The transmitter  206  transmits the electromagnetic waves with vertical linear polarization  302  in one mode and with horizontal polarization  306  in another mode. It can be seen that the vertical polarization is more conducive to line of sight transmission close to the ground as opposed to horizontal polarization which penetrates buildings more efficiently. Thus, the closer a mobile unit is to a building, the more attenuation that will occur. By changing the polarization, it can be seen that the amount of power transmitted through the building will increase. 
     Referring now to  FIG. 4 , there is illustrated a diagrammatic view of one embodiment wherein the antenna at the base station has the phase thereof modified to vary the polarization on the transmit signal. This will effectively manage the power level at the transmitter thus potentially reducing the power requirements for a given base station. In this embodiment, two E-field antennas  402  and  404  are provided in an orthogonal cross-configuration. This will result in vertical polarization if they are phased correctly. The base station transmitter generates a signal that is input to a phase shifter  406  which is operable to adjust the relative phase to a first attenuator  408  that drives the antenna  404  and the second attenuator  410  drives the antenna  402 . By varying the difference between the phase, up to 90°, the polarization could be varied from vertical to horizontal. There is also provided an attenuation control block  412  to vary the power delivered to the antenna for a particular channel. As noted herein above, for each mobile unit, a call can be connected using, for example, a CDMA protocol. However, when two mobile units are communicating on the same frequency, they can be accommodated utilizing Welch coding. However, the carrier is the same and, as such, the polarization can only be varied for one of the mobile units. As such, in a situation like this, a decision would have to be made to accommodate both of the mobile units, i.e., the polarization might be varied half way between the needs of both. 
     Although two E-field antennas are illustrated, it is possible to use one E-field antenna and one H-field antenna. Also, two orthogonal ring antennas could be utilized. What is utilized to vary the electromagnetic properties of the transmitted signal is some type of antenna control to vary the electromagnetic properties of the antenna. Alternately, the actual physical orientation of the antenna could be changed. However, this would not be feasible on a per-user basis but, rather, only on an overall gross adjustment. This would not be done more than once or twice in a short period of time. Additionally, there may be other electromagnetic properties that could be varied to better match the transmitted signal to the receive signal within the particular transmission medium in which the signal is transmitted. Even multiplexing of different physical antennas could be utilized. Although polarization is illustrated as the electromagnetic property to be manipulated, other techniques are contemplated. 
     Referring now to  FIG. 5 , there is illustrated a diagrammatic view of the power control scheme for WCDMA. This is essentially a closed loop power control (PC) which is a combination of outer and inner loop closed loop control. The inner (also called fast) closed loop PC adjusts the transmitted power in order to keep the received Signal-to-Interference Ratio (SIR) equal to a given target value. This SIR target is fixed according to the received BLER (Block Error Rate) or BER (Bit Error Rate). The setting of the SIR target is done by the outer loop PC, which is part of a radio resource control layer, in order to match the required BLER. The update frequency of the outer loop PC is approximately 10-100 Hz. The BLER target is a function of the service that is carried. Ensuring that the lowest possible SIR target is used results in greater network capacity. 
     The inner closed-loop PC measures the receive quality, defined as the received SIR and sends commands to the transmitter (i.e., the mobile unit in the case of an uplink and the base station in the case of a downlink) for the transmitted power update. In order to estimate the received SIR, the receiver estimates the received power of a connection to the power control and the received interference. The obtained SIR estimate (noted SIR est ) is then used by the receiver to generate PC commands according to algorithms set forth in the 3GPP specification, (3GPP TS 25.214 v 4.1.0 2001-06) “physical layer procedures (FDD) (release).” In one of these algorithms, the transmitted power is updated at each of one of a plurality of time slots, these time slots being 10 or 15 ms. It is increased or decreased by a fixed value. If SIR est  is greater than SIR target , then the command sent to the other end is a “0” requesting a transmit power decrease. If the SIR est  is less than SIR target , then the command transmitted is a “1” requesting a transmit power increase. The second algorithm of 3GPP is a slight variant of the first algorithm, wherein the transmitted powers may be updated every five time slots, which simulates smaller power update steps. 
     The power control step size is a parameter of the fast (inner) closed loop PC. In the case of the uplink, it is equal to 1 or 2 dB in the WCDMA system. Values smaller than 1 dB can be emulated by taking larger PC update periods for the second algorithm. The power update step size may be chosen according to the average mobile speed and other operating environmental parameters. For the down link, power update step sizes of the same magnitude could be utilized. 
     The difference between the phase control and the power control is that a command is sent from the mobile unit to the base station to change the phase. The mobile unit can, in one embodiment, alternate between power and phase by first requesting a phase change to optimize the phase, followed by the conventional power control algorithm. For the phase control algorithm, the outer loop is controlled by analyzing the BER or even the Frame Error Rate (FER) to determine if there is an error above a predetermined threshold. This threshold is the target threshold period and, if the error rate is below the target threshold, a request for a phase change is sent. The phase is changed and then the BER or FER evaluated. If it is worse, a command is sent to reverse direction of the phase change. The base station will then increment two increments, i.e., it will erase the first change and make a change in the opposite direction. If the BER or FER improves, then a signal is sent for an additional change in that direction and this will continue until the Bit Error Rate decreases, at which time a command will be sent to reverse the direction. This will be interpreted by the base station as fixing the phase as that is the operable phase for this instant in time. The mobile unit will then switch over to the power control algorithm and then optimize the power. Thus, the decision as to the base controller is made by evaluating the BER of the received signal and adjusting the phase in one direction or the other until the appropriate minima in error has been achieved. This is illustrated in  FIG. 6  wherein the Bit Error Rate is evaluated at a point  602  in the polarization phase. The move is made in the wrong direction to a point  604  in the polarization phase which increases the BER. Thus, a move will then be made at a point  606  in the polarization phase and the BER evaluated. Then a move will be made to a point  608  in the polarization phase. At point  608 , the BER is approximately the same so an additional move may be made to a point  610  in the polarization phase to again evaluate the BER to determine if it in fact has worsened and, if so, this indicates that a move can be made back to point  608  or point  606  in the polarization phase. This is basically a curve fitting algorithm to determine the minima of the BER as a function of the polarization phase. It may be that the polarization phase can be dithered between point  606  and point  608 . In any event, for this particular mobile unit, this will be the best polarization phase. 
     Referring now to  FIG. 7 , there is illustrated a flow chart depicting one scenario for varying the electromagnetic properties, vertical linear polarization in one example, at the base station. The program is initiated at a block  702  and then proceeds to a block  704 . At block  704 , the open loop power is set. The open loop power, as described herein above, relates directly to the path loss. As the name suggests, this control has no feedback and it simply sets the initial power at which the mobile unit should transmit. In this manner, the mobile unit can at least receive information from the base station. The program then flows to a decision block  706  to determine if the phone is in the phase control mode or the power control mode. Either mode can be set as the default mode with the following mode being the other. In this embodiment, the phase mode is set as the default mode and the program will flow along the phase path from the decision block  706  to a function block  708  to measure the error rate, either the BER or the FER. It should be understood that the mobile units are legacy units, since most cellular systems have a lot of flexibility with respect to the base stations but the hardware in the mobile units is fairly well fixed and defined by manufacturers of the equipment. Typically, the base station will have more flexibility than the mobile unit. As such, the only available indicator of some parameter that can be improved by increasing power is the error rate of the data. If there is an issue with respect to an error rate, be it the BER or the FER, an increase in power can sometimes improve this. Thus, the measurement of the BER/FER provides an indication that the power can be reduced or increased. As described herein, the power is controlled by changing the phase of the antenna, i.e., the electromagnetic properties thereof, in order to improve the power delivered to the mobile unit. 
     Once the BER/FER is measured at the function block  708 , the program flows to a function block  710  to send a phase change command to the base station. This is facilitated via a control channel. This is similar to a request for an increase in power or a decrease in power. This phase change command is interpreted at the base station as a request to enter into a particular mode for changing the phase. However, the base station has no knowledge of whether the phase should be changed in a leading direction or a lagging direction. Thus, one direction or the other would be chosen as the default direction. It may be that the increments are in 1° increments, 5° increments or 10° increments. This is up to the designer of the system. Once the phase change command has been sent, the base station will change the phase. The program at the mobile unit will then flow to a decision block  714  to again determine if the BER/FER changes in a positive direction or a negative direction. If in the positive direction, this indicates that the error has increased and then the program will flow to a decision block  716  to determine if the previous change in the BER/FER were a negative change. If so, this would indicate to the overall system that the minima had been achieved in the last phase change. If so, the program will flow along a “Y” path to a function block  718  wherein a “finish” command would be sent back to the base station. When the base station receives this finish command, it would know that the last change caused the error rate to increase and it would jump back to the last phase value. The program then would be returned back to the input of the decision block  706 . However, if at the decision block  716 , it was indicated that the last change had not resulted in a decrease in the error rate, then the program would flow to a function block  720  to send a “+” command back to the base station. This would indicate to the base station that it had changed the phase in the wrong direction. This would cause the base station to change the direction of phase change and possibly jump back two increments such that it would pass through the last increment, and then the program would flow back to the decision block  714  to make a change in the opposite direction. Again, the BER/FER would be checked and, if it again changed in the positive direction, i.e., the error rate increased, this will result in again the “+” being sent back to the base station. This will continue until the BER/FER decreases, at which time the program would flow to a function block  722  in order to indicate to the base station that the direction was correct and this would continue until the BER/FER increased, which would cause the program to flow along the path to the function block  718 . 
     When the “finish” command is sent, as indicated by the function block  718 , the program flows back to the input of the decision block  706 , this changes the mode to the power control mode. This would cause the program to flow from the decision block  706  to a function block  724  in order to set the power on the forward link. This is the conventional process for optimizing the communication link. 
     Referring now to  FIG. 7   a , there is illustrated a flow chart depicting the operation of changing polarization from the view point of the base station, which is initiated at a block  728  and then proceeds to a decision block  728  and then proceeds to a decision block  730 . The decision block  730  determines if the phase change mode has been selected. This is done in response to receiving the phase change command along the control channel from the mobile unit. The program then flows along the “Y” path  732  in order to select a default direction. As noted herein above, either direction could be utilized, as the polarization of the signal is unknown. Again, this particular example deals with polarization as being the change in the electromagnetic property that is being altered. However, it should be understood that any other property of an electromagnetic signal could be altered in order to improve the power or the reception at the antenna. 
     Once the default direction has been sent, the program flows to a function block  734  in order to increment the phase. The program then flows to a function block  736  to wait for a command from the mobile unit. If it is the finish command, the program flows along the “Y” path to an END block  738 , as this is indicated as being the minima. If the finish command is not received, the program flows to a decision block  740  to determine if the “+” command was received. If so, the program flows along a “Y” path and the direction is changed at function block  744  in the opposite direction, as this is an indication that the BER/FER is increasing. The program then flows to a function block  734  to increment the phase change. However, the increment aspect of function block  734  will be changed to increment by two in the opposite direction, in one example. 
     If the “+” command was not received at decision block  740 , the program will flow along the “N” path to a function block  742  in order to process the “−” command, as this command would have been received if the finish command or the “+” command had not been received. The command will be processed by going back to the input of function block  734  to increment the phase. This will, of course, continue until the finish command is received. 
     Referring now to  FIG. 8 , there is illustrated a flow chart depicting another scenario as to when the power control and the phase control are sequenced. This is initiated at a block  802 . The program then flows to a function block  804  and the forward/reverse power are set along the forward link and the reverse link. This is the conventional operation. The program then flows to a decision block  806  to determine if a particular time window is present. This time window is a predefined time window during which the phase changes to the polarization will be effected. If the system is within the time window, the program will flow along the “Y” path to a function block  808  to process the phase control algorithm. If not, the program will flow along an “N” path from the decision block  806  around the function block  808 . Both will flow to a return block  810 . 
     Referring now to  FIG. 9 , there is illustrated a flow chart depicting an alternate embodiment when the power control and phase control are sequenced. This is initiated at a block  902  and the proceeds to a function block  904  to set the forward/reverse power, similar to the block  804 . The program then flows to a decision block  906  to determine if the link is active, i.e., if there is an active call on that link. If so, the program will follow a “Y” path to a function block  908  to process the phase control algorithm to vary the polarization angle of the base station. The program will then flow back to the input of the function block  904 . If the link is not active, the program flows along an “N” path from decision block  906  to the input of decision block  904 . 
     Referring now to  FIG. 10 , there is illustrated a diagrammatic view of a cellular system utilizing polarization control at the base station wherein there are two mobile units  1002  and  1004 , each disposed within a separate microenvironment  1006  and  1008 , respectively. Both of these microenvironments are different such that the effective power levels transmitted along the forward link to each of the mobile units  1002  and  1004  differ, specifically as a result of a polarization change in the vertical linear polarization of the antenna. The problem is that both of these may be on the same channel. The reason for this is that both of these units being on the same channel have a problem in that they are not in a time diverse slot, i.e., they both receive the communication at the same time slot on the same frequency. Current WCDMA systems provide for power control on a per mobile unit basis but do not provide for separating communication and time. In this case, although Welch coding can be utilized to distinguish the calls, the polarization must be averaged between the two units. This procedure would require one unit to determine its optimum polarization and then the second unit to determine its optimum polarization. The base station would then select a polarization that would provide a selection between the two. This is effected via the central RNC (Radio Network Control) block  1010 . 
     Referring now to  FIG. 11 , there is illustrated an alternate embodiment wherein the base station  102 , instead of providing control on a mobile unit by mobile unit basis, provides the control in aggregated sections. The aggregated sections are illustrated as two sections  1102  and  1104 . The section  1102  is a geographical area wherein a plurality of mobile units  1106  are disposed. Each of these mobile units  1106  will operate in similar surroundings, i.e., the polarization for each of these is not that different. It may be that the polarization change or the optimum polarization can be determined for all of the units  1106  and they all have a similar polarization change. Therefore, when transmitting to this section, the polarization will be selected for that aggregated group of mobile units. Thus, only one polarization change needs to be determined for those mobile units. This is similar with respect to the section  1104  having a plurality of mobile units  1108  disposed therein. In some systems, the antenna can be “sector,” such that the certain sections of the area can be called out. 
     Referring now to  FIG. 12 , there is illustrated a flow chart depicting the aggregation of mobile units. In this scenario, which is initiated at a block  1202 , the base station will collect data from all of the mobile units within this area or from a defined sample set. It may be a random sample set based on time or it may be based on a command somewhere on the control channel from the base station for every 100 th  mobile unit that requests a power control change. This would provide some indication to the base station of a possible desired polarization which statistically a large number of the phones would be requesting. Therefore, the program would flow to a function block  1204  wherein an optimum phase would be determined for particular mobile units within the set or within the entire system. It could be that some of the legacy phones are more adaptable to polarization and these phones would be utilized. This information is then accumulated in a function block  1208  and then the program flows to a function block  1210  to determine the setting for the base station. This could be multiple settings which would change over time or could be a single setting that was based upon the phones, the assumption being that once the polarization is changed, the microenvironments would have better receptions and the change was not required on a frequent basis. The program then flows to a decision block  1212  to determine if this is a sectored system. If so, the program flows along a “Y” path to set the polarization by the sector, as indicated by a function block  1214  or along an “N” path to a function block  1216  to set the polarization change for the entire base station. The program will then flow to a return block  1218 . 
     Referring now to  FIG. 13 , there is illustrated a diagrammatic view of the overall system which requires a base station  1302  and a mobile unit  1304 . As noted herein above, the base station  1302  has an antenna  1306  which has certain electromagnetic properties that are fixed by the associated transmitter and the physical structure of the antenna. This, of course, can be changed across the forward link when it impinges an antenna  1310  of the mobile unit  1304 . As described herein above, the base station is the most flexible device in conventional cellular telephone systems. Thus, the electromagnetic properties thereof can be varied, as indicated by a variation block  1312  to vary the electromagnetic properties of the forward link. This is facilitated via a control channel  1316 . This control channel allows the mobile unit  1304  to monitor its signal strength and certain parameters of the received data to make a determination that power should be increased. The base station  1302 , in conjunction with the mobile unit  1304 , will effectively change the electromagnetic properties of its antenna  1306 . However, alternatively, the reverse link could be further controlled to coordinate with the base station such that the base station could send command signals along a command channel  1320  to mobile unit  1304  which has a variation block  1322  associated with its antenna  1310 . The electromagnetic properties of the antenna  1310  could be varied to further reduce the power of the reverse link. This would significantly reduce the amount of power that is required to be transmitted by the mobile unit  1304 , thus reducing the drain on its battery. Thus, either link could be controlled and either transmitter could be controlled to optimize the electromagnetic properties at the receiving antenna. Also, as noted herein above, this would require a fairly flexible mobile unit  1304  that would have the ability to vary the properties of its antenna. This, of course, is not practical with respect to legacy units but future units could be adapted for such. 
     It will be appreciated by those skilled in the art having the benefit of this disclosure that this polarization control for cell telecommunication system provides an alternate technique to improve reception in varying environments without increasing power. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.

Technology Classification (CPC): 7