Block boundary detection for a wireless communication system
AssigneeXilinx, Inc.
InventorsRaghavendar M. Rao, Christopher H. Dick
Life of this patent
Estimating the term…
Abstract
Method and apparatus for block boundary detection is described. A signal is received. The signal is quantized to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples. The sequence of samples and a reference template including totaling partial results from the at least one correlator are cross-correlated to provide a result, the result being a symbol timing synchronization responsive to the cross-correlation also known as block boundary detection. The cross-correlation is provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.
Claims20
A method for block boundary detection, comprising:
- receiving a signal;
- quantizing the signal to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples;
- cross-correlating as between the sequence of samples and a reference template including totaling partial results from the at least one correlator to provide a result, the result being a symbol timing synchronization responsive to the cross-correlating;
- the cross-correlating provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.
A method for block boundary detection for when a system clock frequency is sufficiently faster than a symbol clock rate, comprising:
- receiving an Orthogonal Frequency Division Multiplexed (“OFDM”) signal having orthogonal sub-signals;
- quantizing the OFDM signal to provide a quantized signal, the quantized signal being a sequence of samples;
- obtaining a cross-correlation result as between the sequence of samples and a reference template in by:
- dividing the sequence of samples of correlation length L into respective portions of sub-correlation length N for L and N integers greater than zero;
- combining by respectively exclusive-ORing each sample within each of the portions of the sequence of samples with a respective coefficient obtained from the reference template to provide interim partial cross-correlation results;
- and
- adding the interim partial cross-correlation results to provide a cross-correlation result.
A cross-correlator for a block of information detector, comprising:
- a re-quantizer coupled to receive an input, the input being an Orthogonal Frequency Division Multiplexed (“OFDM”) signal having orthogonal sub-signals for providing symbols in parallel;
- sub-correlators coupled to the re-quantizer to obtain a sequence of samples responsive to the input, the sub-correlators including:
- an address sequencer configured to provide a sequence of vector addresses and an associated sequence of coefficient addresses;
- vector storage coupled to receive the sequence of samples and to store at least a portion of the sequence of samples, the vector storage coupled to receive a vector address of the sequence of vector addresses, the vector storage configured to provide a digital vector associated with a sample of the portion of the sequence of samples stored in the vector storage and located at the vector address received;
- coefficient storage coupled to receive a coefficient address of the sequence of coefficient addresses and configured to provide a digital coefficient responsive to the coefficient address received, the coefficient storage configured to store at least a portion of a preamble of a block of information;
- an array of exclusive-OR gates coupled to receive the digital vector and the digital coefficient;
- and
- an adder tree coupled to the array of exclusive-OR gates configured to add output obtained from the array of exclusive-OR gates to provide a digital cross-correlation result to acquire symbol timing of the input.
Dependencies are inferred from the claim text.