Broadcom Communications, Bangalore, INDIA (Nov 2010 - Present)
Engineer, Staff - I, System Design - Mobile & Wireless Group
Project : BCM21890
A single chip 2G/3G/4G user-end modem supporting GSM, HSPA+ and 3GPP-LTE standard.
Role:
In a current scenario, when UE is connected to the serving eNB, a list of neighbor eNB is advertised to all the corresponding connected UE's by the serving eNB. All the UE are requested to run the background received signal strength measurement(RSSI) on the given list and transmit the results to the serving eNB. Based on these results, serving eNB decides when the corresponding UE can be handover to the neighbor eNB. Whereas, in LTE cell measurement request can be adverstised as well as unadvertised. Thus in the case of unadvertised request, UE is suppose to perform network scanning over different frequencies and networks and send back the measurement results to serving eNB.
As a part of 7 member LTE Mobility team, I was responsible for,
Design and implementation of PHY layer based LTE Intra Cell scanning and measurement algorithms on CEVA-XC DSP and ARM processor.
MAC Integration of the complete cell search and testing & analysis using R&S and Aeroflex test setup.
During May 2012, I travelled to Broadcom -San Diego office to successfully debug the LTE-RRM TC's.
Worked on the design of Inter-RAT scan and measurements.
Prior to leaving Broadcom, I worked on the design of Dual carrier cell scan and provided offsite technical support to IOT team.
Beceem Communications Pvt. Ltd. , Bangalore, INDIA (July 2010 - Nov 2010)
Design Engineer, PHY-SW Group
Project : BCS500
4G Multimode user-end software defined radio modem supporting IEEE 802.16e, m and 3GPP-LTE standards with both Time Division Duplexing (TDD) & Frequency Division Duplexing (FDD) configuration.
Role:
In a current scenario, when a subscriber station (SS) is switched on or goes out of contact with the serving base station (BS), it starts listening to all nearby BS’s downlink (DL) transmission without any prior knowledge of all tuning parameters such as the start and end of DL transmission, center frequency of incoming OFDMA frame and pseudo-noise code of nearby BS's. Thus it requires initial synchronization with BS which involves finding integer (IFO) and fractional frequency offset (FFO), timing offset and strongest BS PN codes. To achieve this, we explore the correlation property of the cyclic-prefix part in OFDM symbol.
As a part of the 3 member Synchronization team, I was responsible for,
Design, fixed-point implementation and verification of complete Synchronization, Handoff and Sync Controller blocks of WiMax using MATLAB & 32-bit CEVA-XC DSP.
Optimizing design to increase the common processing blocks of LTE and WiMax, thus decreasing the Inter-RAT Handover & Sync-time during cross-technology transition.
Real time testing of these blocks on Cadence Palladium hardware tools.
Finally, my intense discussion with AGC and Sample Processor, Rx Transport and FFT Controller team has helped me to completely understand and bring out the finer nuances between two 4G technologies WiMax and LTE.