The last decade was a great one for Qualcomm (NASDAQ: QCOM), the largest mobile chipmaker in the world. Its mobile SoCs dominated the smartphone market and forced out rivals like Texas Instruments, Broadcom, and NVIDIA. Its massive patent portfolio bolstered its bottom line with high-margin royalties, which let it hike its dividend annually for 14 straight years.But the next decade could be tougher for Qualcomm, which faces stiff competition in mobile chips and regulatory pressure to lower its royalty rates.