Multi-millisecond ranging in ultra-wideband systems

A wireless apparatus comprising:

• a radio frequency circuit configured to downconvert a plurality of ultra-wideband (UWB) multi-millisecond (MMS) fragments to generate a plurality of received MMS fragments;
• a plurality of accumulators configured to process each of the plurality of received MMS fragments using a plurality of carrier slice CFO values, wherein the accumulators and carrier slice CFO values are in one-to-one correspondence, resulting in a number of fragment-accumulation signals per fragment;
• a plurality of banks of timing processing units, wherein each of the plurality of accumulators is coupled to a corresponding bank of timing processing units, and wherein, for each fragment, the plurality of banks of timing processing units apply parallel fragment-dependent timing offset correction to each corresponding fragment-accumulation signal, yielding timing-corrected fragment-accumulators, one for each of a plurality of timing slice CFO hypotheses;
• and
• a processor configured to:
• combine the timing-corrected fragment-accumulators for each of the plurality of timing slice CFO hypotheses over the plurality of MMS fragments to yield a plurality of combined final accumulators;
• and
• identify one of the plurality of combined final accumulators as a selected final accumulator based on at least one criteria.

A wireless communication device comprising:

• a memory configured to store an initial range of carrier frequency offset (CFO) values and a coarse timing estimate of a start of a plurality of multi-millisecond (MMS) fragments;
• an ultra-wideband (UWB) receiver configured to receive the plurality of MMS fragments, wherein for each MMS fragment, the receiving comprises:
• performing coherent fragment accumulation using parallel processing for a plurality of carrier slice CFO values within the initial range, resulting in a number of fragment-accumulators;
• and
• applying parallel fragment-dependent timing drift correction to each corresponding fragment-accumulator, yielding a plurality of timing-corrected fragment-accumulators, one for each of a plurality of timing slice CFO hypotheses, and
• a processor configured to:
• after receiving the plurality of MMS fragments, for each of the plurality of timing slice CFO hypotheses, combine the timing-corrected fragment-accumulators yielding a plurality of combined final accumulators;
• and
• identify one of the plurality of combined final accumulators as a selected final accumulator based on at least one criteria.