Flexible correlation and queueing in CDMA communication systems
AssigneeMotorola, Inc.
InventorsYun Kim, David P. Gurney, Anthony R. Schooler, Zhuan Ye
Life of this patent
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Abstract
A programmable correlator for a communication system includes an input queue coupled with an analog-to-digital converter (ADC). The input queue includes a random access memory (RAM) wherein sampled data streams from the ADC are written into the RAM. The input queue has two banks of memory of width 2M. A flexible complex correlator is operable on M samples. The correlator is coupled to read M complex samples out of 2M samples from the input queue. A pseudo-noise (PN) crossbar unit operates to rotate a generated PN code to match a rotation of the input queue data in the complex correlator.
Claims20
A programmable correlator apparatus comprising:
- an input queue coupled with at least one input device, the input queue including random access memory (RAM) wherein data streams from the at least one input device is written into the RAM, the input queue having two banks of memory having an aggregate width 2M;
- and
- a programmable correlator operable on a number M samples simultaneously, the correlator coupled to read M samples out of 2M samples from the input queue.
A programmable correlator apparatus comprising:
- an input queue coupled with at least one analog-to-digital converter (ADC), the input queue including random access memory (RAM) wherein sampled data streams from the at least one ADC is written into the RAM, the input queue having two banks of memory, wherein each bank of the RAM is M×2K wide, where M is the number of samples read into a correlator and K is the number of bits in each real and imaginary data sample;
- a programmable complex correlator operable on M samples, the correlator coupled to read M complex samples out of 2M samples from the input queue;
- and
- a pseudo-noise (PN) crossbar unit, the crossbar unit operable to re-order a generated PN code sequence to match a rotation of the input queue data in the correlator.
A method for correlation, the method comprising the steps of:
- providing a programmable correlator that can correlate M samples in parallel, and an input queue with a dual bank random access memory (RAM) having a width of 2M for writing a number K-bit samples;
- writing samples into the input queue;
- reading out M of 2M samples such that no two column addresses are simultaneously accessed per bank of RAM;
- and
- correlating the M samples of data in parallel.
Dependencies are inferred from the claim text.