Title of Invention

METHOD FOR DYNAMICALLY INCREMENTING TRANSMITTING POWER FOR A USER EQUIPMENT IN A RANDOM ACCESS CHANNEL

Abstract

The present invention relates to a Method for a variable step size is defined, where the step size is related to the initial power calculation. The network broadcasts the various thresholds, and the corresponding step sizes for the UE to apply during retransmissions. According to the invention, the network defines a set of power calculation thresholds (e.g. Threshold1, Threshold2 etc) for the UE. For each threshold, the network also defines power ramping step size (e.g. A1, A2 etc). The UE first calculates initial power that is to be used for sending a preamble to the base station. Next, the UE compares the calculated initial power lies with the thresholds. If the initial power is less than Thresholdl, the UE applies A1 for ramping up the power in subsequent retransmissions. If the initial power is less than Threshold2 but greater then Thresholdl, the UE applies A2 for ramping up the power in subsequent retransmissions. As per the method, for a set of power ramping step sizes (A1, A2, A3 etc.), A1 will be greater than A2, A2 will be greater than A3, and so on. A higher value of A is applied for a low initial power calculation whereas a lower value of A is applied for a high initial power calculation. Further, the number of retransmissions (N) allowed for a UE will depend on the value of A. Smaller the value of A, greater is the value of N.

Full Text

FIELD OF THE INVENTION The invention relates to the field of communication protocols. In particular, the invention proposes a method for dynamically incrementing transmitting power for I a User Equipment (UE) in a Random Access Channel (RACH). More particularly the present invention relates to method for controlling random access retransmission parameters in 3gpp LTE for inter-cell interference mitigation. DESCRIPTION OF RELATED ART Power control for non-synchronized random access The power control scheme shall be designed assuming no intra-cell interference from data transmissions (i.e., TDM/FDM operation). Open loop power control is used to determine the initial transmit power level. It is possible to vary the random access burst transmit power between successive bursts using: • Power ramping with configurable step size including zero step size for both FDD and TDD case • Per-burst open loop power determination for TDD case only • Typically to calculate the open loop transmits power the following parameters are required: o DL reference signal transmit power - broadcasted by the cell o DL reference signal receive power - measured by the UE o UL received interference on the random access resources - measured and broadcasted by the cell o Constant Value - configured and based e.g. on the non-synchronized random access burst quality target • Then the random access burst transmit power (lnitiaLPower_Calculation) can be calculated as A - B + C -+D. • Also, Preamble retransmission power level may be the same as or set larger than the initial preamble transmission power level in steps of Pramp dB with pramp≥ 0. The concept of having a set of predetermined thresholds to be used for comparing transmission power of a UE in a Random Access Channel has been identified in US 6,587,672 and US 2007/0115872. Patent US 6,587,672 and patent application US 2007/0115872 also discuss calculating power ramping step size dynamically by the UE depending on the comparison. However, in both the results, ramping up of the signal power is carried out based on the response received by the transmitter from the receiver. Further, neither of the patent/patent application explicitly mentions using this concept in LTE systems. SUMMARY OF INVENTION The present invention in general relates to 3GPP Release 8 protocols: Goals of random access power control The goals of a design of random access power control are as follows: • Minimize access delay • Minimize inter-cell and possibly intra-cell interference due to random access • Minimize UE power consumption/the transmit power required to receive non-synchronized random access bursts with a quality that guarantees a low detection error probability Therefore, a random access PC algorithm is a trade-off between the access time and UE power consumption/inter-cell interference. More particularly, the present invention relates to Method For Controlling Random Access Retransmission Parameters In 3gpp LTE For Inter-Cell Interference Mitigation The present invention relates to the field of communication protocols. In particular, the invention proposes a method for dynamically incrementing transmitting power for a User Equipment (UE) in a Random Access Channel (RACH). According to the invention, the network defines a set of power calculation thresholds (e.g. Thresholdl. Threshold2 etc) for the UE. For each threshold, the network also defines power ramping step size (e.g. A1, A2 etc). The UE first calculates initial power that is to be used for sending a preamble to the base station. Next, the UE compares the calculated initial power lies with the thresholds. If the initial power is less than Thresholdl, the UE applies A1 for ramping up the power in subsequent retransmissions. If the initial power is less than Threshold2 but greater then Thresholdl, the UE applies A2 for ramping up the power in subsequent retransmissions. As per the method, for a set of power ramping step sizes (A1, A2, A3 etc.), A1 will be greater than A2, A2 will be greater than A3, and so on. A higher value of A is applied for a low initial power calculation whereas a lower value of A is applied for a high initial power calculation. Further, the number of retransmissions (N) allowed for a UE will depend on the value of A. Smaller the value of A, greater is the value of N. Accordingly the invention explains a method for controlling random access retransmission parameters in 3 GPP LTE for inter-cell interference mitigation wherein the said method involves the step of defining a set of power calculation thresholds for the UE by the network and defining power ramping step size for each threshold by the network. These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1 depicts Handling resource allocation after DRX DETAILED DESCRIPTION OF INVENTION The preferred ennbodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. In case lnitial__Power_Calculation is low; this would indicate a good DL link (if all the other factors don't change much) might be due to nearness of the nodeB. Under this scenario Ideally the RACH should get a Preamble response. If however there is no response, it can be because of repeaters in the network configuration; thus UE would need to apply a higher power in the next retransmission. Hence the power ramping can be higher. In case lnitiaLPower_Calculation is high, may be because the UE is far (cell-edge), power ramping applied in the next re-transmission can be lower, to minimize inter-cell interference. Thus, we would propose that the Network defines a set of power calculation thresholds, and for each threshold defines the power ramping step size, as depicted in the figure above. Thus, by the procedure:- UE evaluates the lnitiaLPower_Calculation; and checks where does the value lie in comparison to the set of Thresholds, if it's less than Threshold 1, it will apply A1 for ramping up the power in the subsequent retransmissions (if need be). In case it could not get a response in the first retransmission, it will check if it is still below Threshold 1 (lnitial__Power_Caiculation + A1) or not, in case it is above the Thresholdl, and below Threshold2, it will apply A2 and so on. In the proposed algorithm, A1 amounts to a larger step size, while A2 amounts to a smaller step size; hence A1 > A2 > A3 > and soon.... Given the method as explained before, its important to note that for cell edge users (High Initial Power Calculation), the A step size chosen is smaller; hence it should be allowed more 'N' i.e. Number of retransmissions, so that cell-edge users can still access the network if the Target Tx Power still is unachievable (at the cost of access delay, and total power consumed by the UE) Thus the proposed method also would like the network to define the 'N' for each Threshold. Network Defines a set of thresholds for Power Calculations, and for each threshold also defines, ■ A to be applied; ? Higher delta for lower Initial Power Calculation, and lower delta for higher initial Power Calculation ? As an implementation, 'A' can be same for every threshold (a fallback to the initial method as per 3GPP-WCDMA) • 'N' to be applied ♦ Lower value of 'N' for Higher delta or lower Initial Power Calculation, and Higher value of 'N' for a lower delta or a higher initial Power Calculation As an implementation, 'N' can be same for every threshold (a fallback to the initial method as per 3GPP-WCDMA The interference caused by the random access channel is largely reduced by the proposed algorithm. The proposed algorithm allows the base station to send a faster acknowledgement back to the mobile. Thus, the access delay is greatly reduced. By the proposed mechanism, UE can reach to the target (TX Power to reach to the network) earlier than the classical method. Also, the proposed mechanism suits a topology where there are repeaters in the downlink. UE can reach to the target in lesser retransmissions, and save on power (in comparison to applying several retransmissions to reach to the TX Power), thus amounting to battery-saving. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart there from. We Claim, 1. A method for controlling random access retransmission parameters in 3 GPP LTE for inter-cell interference mitigation wherein the said method involves the step of defining a set of power calculation thresholds for the UE by the network and defining power ramping step size for each threshold by the network. 2. The method as claimed in claim 1, further comprising the steps of the UE calculating initial power that is to be used for sending a preamble to a base station. 3. The method as claimed in claim 1, further comprising the steps of the UE comparing the calculated initial power which lies with the thresholds. 4. The method as claimed in claim 1, wherein if the initial power is less than first threshold, the UE applies a first power ramping step size for ramping up the power in subsequent retransmissions. 5. The method as claimed in claim 1, wherein if the initial power is less than a second threshold but greater than a first threshold, the UE applies a second power ramping step size for ramping up the power in subsequent retransmissions. 6. The method as claimed in claim 1, wherein for a set of power ramping step sizes, a specific power ramping step size will be greater than the next power ramping step size. 7. The method as claimed in claim 1, wherein higher value of step size is applied for a low initial power calculation whereas a lower value of step size is applied for a high initial power calculation. 8. The method as claimed in claim 1, wherein the number of retransmissions (N) allowed for a UE depend on the value of step size where smaller the value of step size, greater is the value of N. 9. A method for controlling random access retransmission parameters in 3 GPP LTE for inter-cell interference mitigation substantially described particularly with reference to the accompanying drawings.

Documents:

2425-CHE-2007 AMENDED PAGES OF SPECIFICATION 05-09-2013.pdf

2425-CHE-2007 AMENDED CLAIMS 05-09-2013.pdf

2425-CHE-2007 EXAMINATION REPORT REPL RECEIVED 05-09-2013.pdf

2425-CHE-2007 FORM-1 05-09-2013.pdf

2425-CHE-2007 FORM-13 05-09-2013.pdf

2425-CHE-2007 FORM-5 05-09-2013.pdf

2425-CHE-2007 POWER OF ATTORNEY 05-09-2013.pdf

2425-che-2007-abstract.pdf

2425-che-2007-claims.pdf

2425-che-2007-correspondnece-others.pdf

2425-che-2007-description(complete).pdf

2425-che-2007-drawings.pdf

2425-che-2007-form 1.pdf