Mobile Terminal processor composition and baseband chip overview

(a) mobile terminal development

A mobile phone to achieve the most important function-call to send text messages, the phone will contain the following parts: RF, baseband, power management, peripherals, software and so on. Recall the history of mobile phones:

1, function phone (Feature phone): Only with baseband chip. Can only be used to call and send text messages.

2, Multimedia Mobile: Use baseband chip + coprocessor acceleration unit. On the basis of the function machine, multimedia functions (such as video, music) are added. MTK is in the era of multimedia mobile phone rise. Of course, thanks to the vast "shanzhai machine". In addition to the CPU, the MTK baseband chip also integrates a very multi-peripheral controller. The functionality of the Feature phone is largely dependent on the peripheral features supported by the baseband chip.

3. Smartphone: ap+ baseband processor CP with application processor. APS can be seen as traditional computers. CP can be seen as a wireless modem.

The interface technology between AP and CP is SPI, UART, USB, SDIO, sharememory and so on. The communication between AP and CP can be done by traditional at command, Mbim and so on, and the functions such as call, short message and mobile internet are complete.

The difference between a feature phone and a smartphone is that the function machine is equivalent to a wireless communication terminal that adds application functionality. There is no operating system, and the smart machine is equivalent to a handheld computer with wireless communication capability, and its software system is similar to the PC software system-the combination of operating system + application software. The two most extensive operating systems for smartphones are Android and iOS systems.

There will also be GPUs dedicated to image processing in the smart machine. And the GPU function will be more and more developed, so we can in the smart machine to watch high-definition movies, play high-quality games.

High-pass baseband chips have the highest performance in the industry. GPU This nvidia is the first level, TI's AP is one of the leading. The development of the future mobile chip is baseband, RF, AP even GPU integrated into a chip--SOC technology, so that the ability to make the lowest power consumption, the smallest area of the chip. This paper describes briefly the function and composition of baseband chip.

(b) What is baseband chip

Mobile terminal support which network system is determined by the baseband chip mode, and the support of the frequency band is determined by the antenna and RF module, baseband chip completion of the mobile terminal access function. The baseband processor is now a highly complex system chip (SoC). It not only supports several communication standards (including GSM, CDMA 1x, CDMA2000, WCDMA, HSPA, LTE, etc.), and provides multimedia functions and interfaces for multimedia displays, image sensors and audio devices, in order to further simplify the design, The power management circuitry required for these compilation circuits is also increasingly integrated.

The RF and baseband sections are the core of the baseband chip.

The current mainstream is the integration of RF transceivers (small signal parts) into the cell phone baseband. The future RF front-end may also be integrated into the cell phone baseband, and with the integration of analog baseband and digital baseband increasingly becoming a trend, the RF may finally be fully integrated into the cell phone baseband chip. The radio frequency section is usually the part of sending and receiving information. The baseband section is usually the part of the information processing. The baseband chip is used to synthesize the incoming baseband signal, or to decode the baseband signal received. The basic frequency is the most important part of the mobile phone, but also the most technical content, only a few manufacturers around the world have this technology. Includes Texas Instruments, Ericsson Mobile platform, Qualcomm, MediaTek, NXP, Freescale, Infineon (today's Intel Mobile Communications Division), Broadcom, Spreadtrum.

Today, with the development of real-time digital signal processing technology, ARM microprocessor, DSP and FPGA architecture become the main way to realize mobile terminal chip.

The ARM main control module realizes the communication between the physical layer and the protocol stack. Receive high-level instructions and run the corresponding tasks. DSP complete the physical layer baseband signal processing, including channel equalization, channel codec and telephone speech codec, multi-mode baseband may exist multiple DSP. When some algorithms in DSP are stable, it is possible to use FPGA to realize these algorithms and reduce the processing burden of DSP.

(iii) Characteristics of modern baseband chips

Baseband chip structure is still based on the MCU+DSP dual-processor core structure, but MCU and DSP processing power has been enhanced, lower power consumption, more and more high performance.

1, the integration of baseband chip has been improving. such as RF RF and digital baseband integration, integrated GPS, WiFi module, integration of many other application interface (such as camera, USB and other application interface).

2, memory organization aspect. To enhance performance, reduce power consumption, and reduce system costs. Both MCU and DSP have a separate cache (s), embedded in the large-capacity static random read memory (SRAM) and even large-capacity flash memory (Flash RAM). Extended memory generally supports synchronous dynamic random memory (SDRAM) and NAND flash RAM.

3, multi-mode mobile terminal baseband chip become a must. Finally, on a baseband chip to support the entire mobile network and wireless network format. Includes 2G, 3G, 4G, WiFi, and more. Multi-mode mobile terminals enable seamless roaming between multiple mobile networks and wireless networks around the world.

For example, 3G baseband chips support GSM/GPRS and WCDMA two modes. Qualcomm Company launched has CDMA2000, WCDMA, gprs/gsm multimode baseband chip. Qualcomm MDM9625 is the world's only one by one single-chip baseband that incorporates seven different RF modes, including CDMA2000 (1xadv/ev-do Rev. A/b), Gsm/gprs/edge, UMTS (WCDMA/TD-SCDMA), LTE ( LTE-FDD/LTE-TDD). Mobile devices based on it can be used anywhere in the world, no matter what changes are needed.

(iv) The current situation of baseband market

Baseband chip technology threshold high, long research and development cycle, capital investment (from the beginning of development to a single stream of Million dollar units), the competition is fierce, so assume that the "station of the wrong team" or the finished product a little later, easy to fall into the loop of step-by-step loss. A lot of manufacturers have given up the baseband business, Freescale, Texas Instruments, Bo Tong, Nvidia has given up the baseband market, Ericsson from the aloof to now once again squeezed into the camp. The domestic Spreadtrum momentum is fierce, after entering the national team, financial support will significantly increase the market has been squeezed into the top three (Qualcomm, MediaTek, Spreadtrum, Intel, Qualcomm occupied the majority of the market 66%, MediaTek 15%, Spreadtrum 5%). Huawei HiSilicon Self-sufficiency cannot be ignored.

Note: What is multi-mode multi-frequency?

Baseband chip multimode refers to the support of a variety of mobile communication mode, the operator's communication mode includes mobile 4g-td-lte, telecom/Unicom 4g-lte FDD, Mobile 3G-TD-SCDMA, Unicom 3G-WCDMA, Mobile/Unicom 2g-gsm, telecommunications 3g-cdma2000, Telecom 2G-CDMA 1x, EVDO, and 3G Evolution HSPA technology.

Multi-frequency refers to the operating frequency under each network environment. Frequency means that each network format, each country has divided several different frequency bands. Let different operators of mobile phone execution in different frequency bands, do not interfere with each other. Popular point, just like the radio. Different frequencies are different stations. Mobile networks also perform on different bands.

Some domestic operating bands are listed:

2G Network

gsm:850/900/1800/1900

3G Network (WCDMA/TD)

Wcdma:2100mhz/1900mhz/850mhz (China Unicom 3G)

Td-scdma:1880-1920mhz/2010-2025mhz (China Mobile 3G)

4G Network

Tdd-lte:1900mhz/2300mhz/2600mhz (China Mobile 4G)

Fdd-lte:1800mhz/2600mhz (4G of China Unicom and Telecom in the future)

The market X-mode X-frequency mobile phone actually has a lot of combinations, such as dual-mode, China is more likely to be three modulo eight-frequency, five-mode ten-frequency, five-mode 13-frequency three. China Mobile is the first to put forward five-mode 13-frequency, simply to support five communication modes and 13 corresponding bands of mobile devices.

Five-mode terminal can support Td-lte, LTE FDD, TD-SCDMA, WCDMA, GSM Five kinds of communication mode, support Td-lte BAND38/39/40,TD-SCDMA band34/39. WCDMA BAND1/2/5. LTE FDD band7/3,gsm BAND2/3/8 and other 10 bands, some terminals can also support Td-lte band41,lte FDD BAND1/17. GSM Band5 and other frequency bands, to achieve terminal global roaming.

Support five-mode 13-band mobile phone, that is able to support China Mobile and Chinese unicom 2G, 3G, 4G, that is, double 4G. This kind of cell phone only wants to plug in Mobile card. Is the 2G, 3G, 4G network that supports mobile. Suppose the plug-in card. Support Unicom 2G, 3G, 4G network. The future of China Telecom's 4G mobile phone listing, will also have support for CDMA 1x/cdma2000 multimode 4G mobile phones, three netcom will eat more and more mobile phones.

Mobile Terminal processor composition and baseband chip overview