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Power-efficient SDR platform handles multimode 4G
Itay Lusky
9/11/2010 10:24 PM EDT
SDR's link to efficiency
As has been shown, different 4G standards share common characteristics. So why isn’t a hardwired ASIC implementation enough? And why is it so important to employ an SDR approach?
Although the different 4G technologies share the same basic OFDM principles, their details differ substantially. The differences begin in basic L1 parameters, such as frame structure, reference signal locations and properties, subcarrier spacing, physical channel definitions and forward error correction schemes. L2 and L3 layers also substantially differ, for example, by handover, idle, and cell selection and reselection procedures.
Meanwhile, the various 4G standards (especially LTE) continue to evolve. 3GPP-LTE, for example, is currently in Release 8, but Release 9 is around the corner. Software-upgradable products provide operators substantial future-proof benefits.
Further, programmability allows support of different algorithmic approaches as a function of channel conditions, allowing dynamic and efficient solution adaptation based on field experience.
Whereas conventional DSPs were up to the task for implementation of legacy 3G standards, that is not the case for multimode 4G. The various 4G standards reach throughputs exceeding 100 Mbits/second, approximately 10 times higher than 3G. In addition, usage of advanced MIMO techniques might increase required processing power exponentially with the number of transmit and receive antennas. Combined, these and other factors cause the required computational load to reach several tens of giga complex multiply-accumulate (GCMAC) operations per second. Conventional DSPs cannot provide such processing power at reasonable area and power consumption metrics.
The suggested solution uses an SDR approach that is adapted to perform common required tasks for 4G applications.
As has been shown, different 4G standards share common characteristics. So why isn’t a hardwired ASIC implementation enough? And why is it so important to employ an SDR approach?
Although the different 4G technologies share the same basic OFDM principles, their details differ substantially. The differences begin in basic L1 parameters, such as frame structure, reference signal locations and properties, subcarrier spacing, physical channel definitions and forward error correction schemes. L2 and L3 layers also substantially differ, for example, by handover, idle, and cell selection and reselection procedures.
Meanwhile, the various 4G standards (especially LTE) continue to evolve. 3GPP-LTE, for example, is currently in Release 8, but Release 9 is around the corner. Software-upgradable products provide operators substantial future-proof benefits.
Further, programmability allows support of different algorithmic approaches as a function of channel conditions, allowing dynamic and efficient solution adaptation based on field experience.
Whereas conventional DSPs were up to the task for implementation of legacy 3G standards, that is not the case for multimode 4G. The various 4G standards reach throughputs exceeding 100 Mbits/second, approximately 10 times higher than 3G. In addition, usage of advanced MIMO techniques might increase required processing power exponentially with the number of transmit and receive antennas. Combined, these and other factors cause the required computational load to reach several tens of giga complex multiply-accumulate (GCMAC) operations per second. Conventional DSPs cannot provide such processing power at reasonable area and power consumption metrics.
The suggested solution uses an SDR approach that is adapted to perform common required tasks for 4G applications.
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