Title of Invention

METHOD FOR DATA TRANSMISSION IN MULTIPLE SPATIAL PATHS BASED COMMUNICATION SYSTEM

Abstract

The invention in general relates to communication technology and in particular relates to a system and method for data delivery in multiple spatial paths based communication system. Based on the CQIs (Channel Quality Indicators) received from the receiver, the data to be transmitted is scheduled on the available spatial paths (spatial layers or multi carriers). In MIMO/Multi-carrier transceivers, the data is transmitted using multiple data sub-streams. Each of the data sub-streams or packets has a flow priority and a QoS (Quality of Service) attribute assigned to it.

Full Text

FIELD OF INVENTION The invention in general relates to communication technology and in particular relates to a system and method for data delivery in multiple spatial paths based communication system. More particularly the present invention relates to a method and system for data transmission in multiple spatial paths based communication system. DESCRIPTION OF RELATED ART In the advanced communication systems, user data is transferred using the multiple antenna systems and multi-carrier communications system. MIMO system uses multiple-input multiple-output (MIMO) techniques that increase spectral efficiency through spatial multiplexing. Similarly in Multi-carrier systems plurality of carriers is used to provide frequency diversity and more bandwidth to provide more system capacity. Such system there is a scope, of making the data delivery more efficient by utilizing the feedback information, which is given by the receiver to the transmitter. In the communication systems using the MIMO techniques, the user data is transferred using the multiple physical antennas. In HRPD Rev C system there are two types of the MIMO modes - namely Single Code Word (SCW) and Multi Code Word (MCW) modes. In MCW mode, multiple encoded streams of data are simultaneously transmitted over M spatial layers. Receiver (e.g. AT - access terminal) calculates the Channel quality indicators (CQIs) and Rank and gives this information to the transmitter (e.g. Access Network). Thus transmitter can use this information in doing the scheduling of various services running between transmitter and receiver using M HARQ channels. In a Multi- Carrier system multiple encoded streams of data are transmitted simultaneously over M carriers. There receiver gives the feedback information for each carrier in terms of the channel quality indicators. Thus transmitter can use this information in doing the scheduling of various services running between transmitter and receiver using M independent HARQ channels. Thus whenever there are multiple encoded streams of data of various services are simultaneously transmitted over M spatial paths (e.g. spatial layers in MIMO system or carriers in multi-carrier system) in a transmitter to a receiver, the feedback (channel quality indicator, rank, etc) information from the receiver can be used in scheduling data packets from these services on the spatial paths. A spatial path can be defined as an independent medium of transmission, which can support a transmission for a HARQ channel transmission and receiver can feedback the channel quality indicator for this channel. In patent no.US20050043031A, titled," Apparatus and method for scheduling resource in a multi user MIMO radio communication system", the invention describes an apparatus and method for scheduling resources according to channel quality in a multi-user MIMO radio communication system. The invention aims at maximizing the entire transmission efficiency of a multi-user MIMO radio Communication system. The system comprises a transmitter or a base station and a plurality of receivers or mobile stations. Each of the base station and mobile stations includes a plurality of transmission antennas and reception antennas, respectively. The base station has a scheduler. The scheduler comprises a pre-selector and transmission pre-coder. The scheduler detects the channel quality information (CQI) fed back from the mobile stations and using this information, it generates the map for assigning time-frequency-transmission antenna resources, for sequential transmission scheduling, to the mobile stations. The pre-selector determines an optimal subset of transmission resources considering class priority, or quality-of-service (QoS) priority, of a corresponding mobile station, a size of packet data buffered in the queues of the base station, and a buffering time of the packet data buffered in the queues of the base station. SUMMARY OF THE INVENTION The proposed invention allows efficient data transmission by a transmitter, by scheduling the data with received feedback information from the receiver. Receiver is computing the channel quality indicators and giving back to the transmitter. This information can be used for data scheduling on the M spatial paths. Data is scheduled on the spatial paths using the flow priority as well the QoS attributes. Data scheduling on spatial paths is done based on the factors like Priority levels, number of HARQ retransmission needed for a packet, ack/nack required or not and assigning weights to QoS attributes. This ensures a good system level and each user's throughput for various services. Accordingly the invention explains a method for data transmission in multiple spatial paths based communication system wherein the data to be transmitted is scheduled on the available spatial layers or multi carriers based on the Channel Quality Indicators (CQIs) received from the receiver and in MIMO/Multi-carrier transceivers, the data is transmitted using multiple data sub-streams where each of the data sub-streams or packets has a flow priority and a QoS (Quality of Service) attribute assigned to it. The QoS is granted by the RAN while creating the flow of the data packets. The data scheduler uses the QoS and flow parameters to allocate, spatial paths to the different flows where the flows are prioritized to get spatial paths with the highest CQI level. While scheduling the data on spatial paths by data scheduler if two flows have the same flow priority, their corresponding QoS attributes are compared and the flow with a pre-defined high-priority attribute is allocated a spatial path with highest CQI. A flow having less number of HARQ retransmissions allocated a higher CQI spatial path to ensure successful delivery of its packets. If the number of flows exceeds the number of spatial paths, the scheduler multiplex the data to be sent on a spatial path based on the priority and QoS attributes. The CQI feedback schedules the data on the spatial paths. QoS attributes are categorized or compared, between the flows to assign the spatial paths. MaxJ_atency,Peak_rate,Max_IP_Packet_Loss_Rate, Delay_Var_Sensitive, FlowProfilelD, Traffic_Class, Bucket_Size, Token_Rate, Packet_Size are criterion to assign the spatial paths to different flows. When flow priority and QoS attributes are same, the data scheduler multiplexes data on a spatial path or does a round robin scheduling of the flows. The spatial paths is chosen based on the block code error correction bits provided between the flows of identical priority and QoS attribute. When the number of flows are more than spatial paths, the flows are multiplexed based on the flow priorities and QoS attributes. When spatial paths are more than data flows, a single flows code words chosen for n (out of M) spatial paths. While scheduling on spatial paths, the multiplexer ensures every packet transmitted occupies the full length of the code word that it can transmit on a spatial path. Spatial paths are chosen based on the number of retransmission required for the packets of the various flows. Spatial paths are chosen based on the number ack/nack enabled or disabled for the packets of the various flows. Flow priority and QoS attributes in a QoS attribute set, is given weights, for a function of selectivity to be calculated per flow, to choose spatial paths for flows. Accordingly the invention explains a system for data transmission in multiple spatial paths based communication system wherein the data to be transmitted is scheduled on the available spatial layers or multi carriers based on the Channel Quality Indicators (CQIs) received from the receiver and in MIMO/Multi-carrier transceivers, the data is transmitted using multiple data sub-streams where each of the data sub-streams or packets has a flow priority and a QoS (Quality of Service) attribute assigned to it. 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 THE DRAWINGS Figure 1 shows the block diagram for data transmission in multi code word, M spiral layers-MIMO system. Figure 2 shows the block diagram for data transmission in multi-carrier system. DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments 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. FIGURE 1 shows the example of a MCW Ml MO transceiver. As discussed above, in MCW MIMO system, data is transmitted using M data sub-streams, adapted to channel, on the M spatial paths. The receiver runs a rank prediction algorithm by which it determines the value of M to be used. Receiver also computes M CQI (channel quality indicator) values, one for each spatial path (data sub-stream), and feeds them back to the transmitter. Transmitter adjusts the transmitted power level on each spatial path (data sub-stream), based on the power control loop and rank, and runs a rate prediction algorithm by which it chooses the packet format for each data sub-stream. FIGURE 2 shows the example of a Multi-carrier transceiver. In this system the M data sub-streams, of N service flows are transmitted to a receiver using the M assigned carriers. There receiver computes the M CQI (channel quality indicators) values, and feeds them back to the transmitter. Transmitter can use this information to select the packets formats to be used for each data sub-stream. The art discussed here, applies to a system where multiple encoded streams of data of various services are simultaneously transmitter over M spatial paths (spatial layers or Multi-carriers). Two examples of such systems are discussed above. In this art the efficient data transmission can be done in transmitter, by scheduling the data with received feedback information from the receiver. Receiver is computing the channel quality indicators and giving back to the transmitter. This information can be used for data scheduling on the M spatial Paths. As we know all the applications are associated with quality of service which is granted by the RAN while creating the flow. In an embodiment, when there are new packets to schedule on the M spatial paths the packets on each path can be chosen based on the associated QoS attributes of the flow and Flow priority. As given in the FIGURE 1 and 2, there are N flows with N granted QoS attributes. The N IP/RLP flows have their dedicated buffers in the data scheduler entity, to pump the data into them. These buffers will have the data corresponding to each IP/RLP flow with associated QoS attributes. The scheduler will implement the rules, to delivers the packets to the turbo coders in physical layer to transmit on the spatial paths. These rules have to be developed in data scheduler by using the QoS parameters and flow parameters. Data scheduler implements a method to schedule the data on spatial paths. The method is as follows: 1. The Flow priority of a flow is a parameter to choose a spatial path having the strongest reported CQI. Lowers priority flow will get the lower CQI reported spatial path. 2. If there are 2 flows having same priority, then the QoS attribute set should be used to choose the spatial paths. The QoS attribute set contains the granted QoS parameters. These parameters can be used to develop the rules for choosing the spatial paths. The important QoS attributes to implement the rules are Max_Latency, Max_IP_Packet_Loss_Rate, and Delay_Var_Sensitive. Other QoS attributes can also be chosen to develop the rules such as Peak_rate, FlowProfilelD, Traffic_Class, Bucket_Size, Token_Rate, and Packet_Size. The maximum latency of a packet can decide to choose a spatial path with highest CQI. A packet with low latency can be given spatial path with lower CQI. Similarly Peak rate, maximum IP packet loss rate and sensitiveness to variation in delay of a flow can decide about the spatial paths to choose. Similarly for given N flow the other QoS attributes can decide about the spatial paths to choose for their respective flows. These attributes can be chosen in order or priority to choose the spatial paths. In an embodiment, Flow priority and QoS attributes in a QoS attribute set, can be given weights, such that a function of selectivity can be calculated per flow, to choose spatial paths for flows. Thus N flows can be mapped on the M spatial paths. (Where N = M or N M). 3. If there are two flows, with identical flow priority and identical QoS attributes then a spatial path can be given based on the round robin scheduling between the two flows, or the packets from both the flows can be multiplexed on the spatial path with highest CQI. Similarly again multiplexing can be done on another lower CQI value spatial path. 4. When there are more flows than the spiral paths, then the spiral paths should be chosen not just based on the flow priority but also based on the QoS attributes defined for each flow. The scheduler can multiplex the data to be sent on a spatial path based on the priority and QOS attributes. 5. If there are more spatial paths than the flows then the scheduler can choose the n (out of M) spatial paths of better CQI level( from highest to lower CQI level) for n code words of a flow based on the flow priority and QoS Attributes. The scheduler can also multiplex the data of 2 different flows on the highest CQI reported path, depending on the QoS attributes. In above stated algorithm, the scheduler schedules the packets on the spatial paths based on the rules as described in the algorithm. The size of the coded packet that can be transmitted on spatial paths is fixed based on the chosen modulation and coding scheme per path for each transmission, which is determined by the CQI reported. In an embodiment, if there is not enough data in the buffer of one flow then, rest of the data can be multiplexed from another flow (scheduled on another lower CQI reported path). This is ensured by the multiplexer. In an embodiment, the spatial path can be chosen based on the number of HARQ retransmissions needed for a packet of a flow. For example if there are 2 flows, having different number of HARQ retransmission specified for its packets, then a higher CQI spatial path can be given to flow which is having lower number of retransmission to ensure a good chance of successful delivery of its packets. In another embodiment, the spatial path can be chosen based on the ACK/NACK enabled or disabled for the packets of the flows. For example if there are 2 flows/packets, where one flow/packet is ack/nack enabled and other is ack/nack disabled then a higher CQI spatial path can be given to flow/packet with ack/nack disabled, to increase the chance of successful delivery of the ack/nack disabled packet. In another embodiment, the spatial path can be chosen based on the types of flow packets. Signaling packets are always more important than the data packets. In this case the signaling packets can be assigned a spatial path with better CQI reported. The above stated algorithm, with all the embodiments, will perform efficient data delivery. The art given above utilizes the feedback information in scheduling the data on the spatial paths. The scheduling is done by the scheduler (FIGURE 6) based on the rules discussed above. This will ensure a good system level and each user's throughput for various services. 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 therefrom. GLOSSARY OF TERMS AND DEFINITIONS THEREOF QoS Quality of Service CQI Channel Quality Indicator AMC Adaptive Modulation and Coding ACK/NACK Acknowledgement / Negative Acknowledgement SCW Single Code Word MCW Multi Code Word MIMO Multiple Input Multiple Output OFDM Orthogonal Frequency Division Multiplexing HRPD REV C High Rate Packet Data - Revision C HARQ Hybrid Automatic Repeat Request IP/RLP Internet Protocol/ Radio Link Control RAN Radio Access Network WE CLAIM 1. A method for data transmission in multiple spatial paths based communication system wherein the data to be transmitted is scheduled on the available spatial layers or multi carriers based on the Channel Quality Indicators (CQIs) received from the receiver and in MIMO/Multi-carrier transceivers, the data is transmitted using multiple data sub-streams where each of the data sub-streams or packets has a flow priority and a QoS (Quality of Service) attribute assigned to it. 2. A method as claimed in claim 1 wherein the QoS is granted by the RAN while creating the flow of the data packets. 3. A method as claimed in claim 1 wherein the data scheduler uses the QoS and flow parameters to allocate, spatial paths to the different flows where the flows are prioritized to get spatial paths with the highest CQI level. 4. A method as claimed in claim 1 wherein while scheduling the data on spatial paths by data scheduler if two flows have the same flow priority, their corresponding QoS attributes are compared and the flow with a pre-defined high-priority attribute is allocated a spatial path with highest CQI. 5. A method as claimed in claim 1 wherein a flow having less number of HARQ retransmissions allocated a higher CQI spatial path to ensure successful delivery of its packets. 6. A method as claimed in claim 1 wherein, if the number of flows exceeds the number of spatial paths, the scheduler multiplex the data to be sent on a spatial path based on the priority and QoS attributes. 7. A method as claimed in claim 1 wherein the CQI feedback schedules the data on the spatial paths. 8. A method as claimed in claim 1 wherein QoS attributes are categorized or compared, between the flows to assign the spatial paths. 9. A method as claimed in claim 1 wherein Max_Latency , Peak_rate, Max_IP_Packet_Loss_Rate, Delay_Var_Sensitive, FlowProfilelD, Traffic_Class, Bucket_Size, TokenJRate, Packet_Size are criterion to assign the spatial paths to different flows. 10. A method as claimed in claim 1 wherein when flow priority and QoS attributes are same, the data scheduler multiplexes data on a spatial path or does a round robin scheduling of the flows. 11. A method as claimed in claim 1 wherein, the spatial paths is chosen based on the block code error correction bits provided between the flows of identical priority and QoS attribute. 12. A method as claimed in claim 1 wherein, when the number of flows are more than spatial paths, the flows are multiplexed based on the flow priorities and QoS attributes. 13. A method as claimed in claim 1 wherein when spatial paths are more than data flows, a single flows code words chosen for n (out of M) spatial paths. 14. A method as claimed in claim 1 wherein, while scheduling on spatial paths, the multiplexer ensures every packet transmitted occupies the full length of the code word that it can transmit on a spatial path. 15. A method as claimed in claim 1 wherein, spatial paths are chosen based on the number of retransmission required for the packets of the various flows. 16. A method as claimed in claim 1 wherein the spatial paths are chosen based on the number ack/nack enabled or disabled for the packets of the various flows. 17. A method as claimed in claim 1 wherein, flow priority and QoS attributes in a QoS attribute set, is given weights, for a function of selectivity to be calculated per flow, to choose spatial paths for flows. 18. A system for data transmission in multiple spatial paths based communication system wherein the data to be transmitted is scheduled on the available spatial layers or multi carriers based on the Channel Quality Indicators (CQIs) Received from the receiver and in MIMO/Multi-carrier transceivers, the data is transmitted using multiple data sub-streams where each of the data sub-streams or packets has a flow priority and a QoS (Quality of Service) attribute assigned to it. 19. A method for data transmission in multiple spatial paths based communication system substantially described particularly with reference to the accompanying drawings. 20. A system for data transmission in multiple spatial paths based communication system substantially described particularly with reference to the accompanying drawings.

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2458-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 01-03-2013.pdf

2458-CHE-2006 AMENDED PAGES OF SPECIFICATION 01-03-2013.pdf

2458-CHE-2006 AMENDED CLAIMS 01-03-2013.pdf

2458-CHE-2006 FORM-1 01-03-2013.pdf

2458-CHE-2006 FORM-13 01-03-2013.pdf

2458-CHE-2006 POWER OF ATTORNEY 01-03-2013.pdf

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2458-CHE-2006 FORM 18.pdf

2458-che-2006-abstract.pdf

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2458-che-2006-description(complete).pdf

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