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5G Cell Phones

5G Cell phones have been designed to meet 3GPP NR specifications. 5G phones should work on radio frequencies in various bands as per country-wise allocations. It uses less than 1GHz, below 6 GHz, and above 6GHz (mmWave) frequency bands. 

It delivers fast uplink/downlink throughput due to Massive MIMO and low latency between 5G networks and UE. The 5G cell phone supports 10 times throughput as compared to 4G phones. 5G phones are backward compatible with 4G technology. 

Block Diagram

A 5G cell phone has the following two major building blocks: 

  • Baseband processing block
  • RF processing block 

Baseband processing block: It constitutes different cores like Application core, Multimedia core, and Communication core, etc. the main use of these cores is that it enables functioning for the operating system, device drivers, interfacing with Mic, camera, screen, etc. It also has a baseband processor containing multi-RAT protocol stack software. 5G cell phone baseband software supports New Radio in both the frequency ranges (FR-1) and (FR-2). This protocol software also needs to support 4G LTE, 3G WCDMA, etc technologies. This protocol software should be able to support advanced baseband signal processing algorithms to enable Massive MIMO, beamforming, and interference suppression features. 

RF processing block: It is responsible to receive and transmit the baseband signals. This block contains RF IC, front end module, LNA, Antenna arrays, and sensors. RF IC enables the co-existence of different radio access signals. 5G cell phones have a different antenna module to support a wide range of frequency bands i.e mm waves, sub - 6GHz, and low-frequency bands. RF section shall have some important sensors like Proximity sensor, Light sensor, Barometer, Magnetometer, Accelerometer, Gyroscope, Thermometer, Iris Scanner, Heart rate monitor, pulse monitor. 

5G cell phone Architecture

It includes 

  • Baseband part
  • Digital RF interfaces such as DigRF
  • ADC/DAC 
  • RF transceiver (Antenna array is used instead of one antenna to support Massive MIMO and beamforming)

Quadplexer: It is used instead of a diplexer to support multiple bands. It is used to multiplex and demultiplex four radio frequencies to/from a single coaxial cable. This helps in reducing cost and weight as well as uses a very smaller area of the phone. It should support mmWave frequency bands. 

RFFE (Radio Frequency Front End) control signals are used to carry TSSI (Transmitter Signal Strength Indicator) and RSSI (Receiver Signal Strength Indicator). 

PMU’s (Power Management Unit) and LDOs (low drop-out regulators): these are used in the beamforming part of the 5G cell phone. They transform the DC voltage of coaxial cable to different power supplies for use in cell phone operation.