The limitations of the development for 4G modems
not only refer to the increasingly complicated wireless standard. Today, the smart phones have to support several wave points. Besides WiMAX and/or LTE, 4G mobile service needs to support a great number of wave points, such as GSM, DV666, EDGG, W-CMDA and HSPA and the latest HSPA+.
Traditional (hard-wired) project is realized by the whole modem to apply hardware. The advantage of this project is able to quicken the pace for first chips to appear in the market. In addition, the hardware designed for some certain standards can ensure the lowest power usually. Nevertheless, just as what mentioned before, this method lacks flexibility, which also can not be in accord with the future development blueprint of products upgrading.
Mixed project is combined with hard-wired design and programmable data processor. The parts needing flexibility of modem will be reflected to programmable DSP core, taking advantage of software to be flexible. The rest parts of modems with CPU-bound and small agility such as FFT will be as the same as hard-wired project to be made by hardware. SDR project is to implement complete software modems, supporting multiple wireless standards on one chip with software.