CEVA Eyes DSP Scale in China’s $65 LTE Handsets

China Mobile’s bid to go for 3-mode Long-Term Evolution (LTE) has led to the first major breakthrough, $65 LTE handsets, and here baseband and application processors provided by chipmakers like Leadcore Technology, MediaTek and Spreadtrum Communications have all one thing in common: DSP cores from CEVA Inc.

The advent of the $65 LTE handsets in the world’s largest mobile phone market could reinvigorate the smartphone boom all over again. Here, it’s important to note that signal processing is the centerpiece in two of the major building blocks of the LTE technology: orthogonal frequency-division multiplexing (OFDM) and multiple-input multiple-output (MIMO). Not surprisingly, therefore, DSP socket supplier CEVA is seeing China’s expected 300 million new LTE subscribers in 2015 with a lot of hope and excitement.

The CEVA-XC soft-modem for LTE baseband chips

In 2014, there was an interesting twist to China’s LTE story when China Mobile decided to reduce the LTE format specifications to 3-mode products. Within the LTE standard domain, 3-mode products support GSM, TD-SCDMA and TD-LTE cellular standards for 2G,3G and 4G wireless communications, respectively. These wireless standards are predominantly used in China, so inevitably, 3-mode LTE would be more suitable for China’s chipmakers and smartphone manufacturers.

The international version—5-mode LTE—supports GSM, W-CDMA, TD-SCDMA, TD-LTE and FDD LTE and favors chipmakers like Qualcomm who have a global footprint. Apparently, China Mobile’s bet to stick with TD-LTE has started to show results with the launch of inexpensive smartphones. And China Mobile, one of the three large cellular operators in mainland China, is expected to consume 50 percent to 60 percent of these 3-mode LTE phones.

CEVA’s Smartphone Sockets

In January 2015, the trade media in China reported Xiaomi launching a $65 LTE phone that sported mobile chipset from Leadcore Technology. Leadcore, which uses DSP cores from CEVA, has actually replaced Qualcomm’s Snapdragon 410 that Xiaomi used in its earlier Redmi 2 handset. Qualcomm uses its proprietary Hexagon DSP cores in the Snapdragon chips.

Likewise, TCL’s upcoming LTE phone for China Mobile is reported to cost $65 and is based on MediaTek’s quad-core MT6582 application processor and LTE MT6290 modem chip. Again, MediaTek licenses CEVA-X DSP cores and subsystems from CEVA. Next up, Spreadtrum, another licensor of CEVA DSP cores, is supplying SC9620 LTE baseband chips to Coolpad and Lenovo handsets. Spreadtrum claims to have shipped 30 million CEVA-powered baseband chipsets.

Lenovo a388t phone features a DSP core from CEVA

Winning DSP sockets in China’s volume 4G wireless market could be a vital breakthrough for CEVA, but the DSP licensor of baseband chips is not putting all its eggs in China’s 3-mode LTE basket. CEVA has also scored an important design win in Samsung’s Galaxy phones.

Samsung is trying to reinvigorate its Exynos SoC with the help of LTE application processors. According to Forward Concepts, which focuses on DSP-centric wireless communications market research, Samsung’s quad-core Exynos ModAP is the Korean firm’s first generation of integrated LTE modem-application Processor solution with multimode LTE connectivity. The second one is the Exynos 300 modem that supports LTE-Advanced. Both modem chips are based on CEVA DSP cores.

CEVA claims to have shipped DSP sockets in more than 1 billion chips in 2013 and around 40 percent of these chips went into mobile phones. Wireless baseband chips inside smartphone are a key volume market for CEVA and China’s great baseband game could well bring the next big growth opportunity for the DSP licensor. According to industry research firm Strategy Analytics, CEVA licensees MediaTek and Spreadtrum rank second and third, respectively, after Qualcomm in the global mobile baseband chip market.

About DSP Socket in Smartphones

The DSP part is now predominantly used in system-on-chip (SoC) solutions for communication and consumer markets, and here, mobile phones constitute the largest segment for DSP cores. All baseband chips carry one or two DSP cores. On the baseband side, the voice signal needs to be digitized and compressed, modulated onto a wireless signal, transferred through the wireless infrastructure to the other end of the call, and decompressed again.

According to a recent newsletter of Forward Concepts, even application processor have now started to deploy DSP functionality, either as co-located DSP cores or as SIMD extensions to the CPU instruction set. On the application processing side of a mobile phone, data files containing video, images and audio need to be decoded and sent to the device’s screen, speakers and headset, all very specific DSP tasks.

CEVA’s DSP solution for mobile handsets

The CEVA DSP cores allow both hybrid and soft modem approaches for developing mobile baseband chips. For the hybrid approach, which mixes hardwired design with a programmable processor, the CEVA-X family of multi-purpose DSP cores enable a high level of concurrent instructions processing as well as low power consumption.

The CEVA-XC family of DSP cores, built on the CEVA-X processors, offers a complete soft-modem implementation, supporting multiple wireless standards concurrently on the same chip in software. They use a single engine for all wireless processing and thus eliminate the need for multiple baseband co-processors. That way, the CEVA-XC DSP cores reduce power consumption and die size related to additional memories, data buffers and overall data traffic.

Also see CEVA and LTE: Happy Together

Majeed Ahmad is author of books Age of Mobile Data: The Wireless Journey To All Data 4G Networksand Essential 4G Guide: Learn 4G Wireless In One Day.