Son of heaven - David Wingrove

The year is 2085, two decades after the great economic collapse that destroyed Western civilization. With its power broken and its cities ruined, life in the West continues in scattered communities. In rural Dorset Jake Reed lives with his 14-year-old son and memories of the great collapse. Back in '43, Jake was a rich, young futures broker, immersed in the datascape of the world's financial markets. He saw what was coming - and who was behind it. Forewarned, he was one of the few to escape the fall.
For 22 years he has lived in fear of the future, and finally it is coming - quite literally - across the plain towards him. Chinese airships are in the skies and a strange, glacial structure has begun to dominate the horizon. Jake finds himself forcibly incorporated into the ever-expanding 'World of Levels' a global city of some 34 billion souls, where social status is reflected by how far above the ground you live.
Here, under the rule of the mighty Tsao Ch'un, a resurgent China is seeking to abolish the past and bring about world peace through rigidly enforced order. But a civil war looms, and Jake will find himself at the heart of the struggle for the future.