Method and device for modulating with Zadoff-Chu sequences
AssigneeTernwaves
InventorJean Canonici
Life of this patent
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Abstract
A method and device for modulating with Zadoff-Chu sequences. Each K-ary symbol to be transmitted is converted into a Zadoff-Chu sequence of preset length N and of preset root r, and the frequency offset q of which is dependent on the K-ary symbol. Various root values may be used to separate distinct uplink and downlink and synchronous or asynchronous communications. The modulating device is implemented in the frequency domain. A demodulating method and device allows the K-ary symbols thus transmitted to be recovered. The demodulating device may be implemented in the time domain or frequency domain.
Claims15
A method for modulating a plurality of K-ary symbols to be transmitted over a transmission channel, wherein each K-ary symbol is transformed into a Zadoff-Chu sequence associated with this symbol, said Zadoff-Chu sequence being of length N, root r and frequency offset q where N is a positive integer such that log2 N≥K, r is an integer such that r>1 and prime to N, q is a relative integer, and that any two K-ary symbols of said plurality are associated with Zadoff-Chu sequences having distinct frequency offsets, each K-ary symbol being modulated in the form of a sequence, of length greater than or equal to 2K, of consecutive complex elements of the Zadoff-Chu sequence associated with said K-ary symbol, wherein the distinct frequency offsets for the Zadoff-Chu sequence are assigned distinctively for two communications.
A modulation device to modulate a plurality of K-ary symbols to be transmitted over a transmission channel, comprising a binary to decimal converter transforming the bits K of each K-ary symbol into a distinct integer value, and a Zadoff-Chu sequence generator, having as input parameters a sequence length N and a root r such as integer r, r>1 and prime to N, as well as a frequency offset q, q being a relative integer, said generator generating, for each K-ary symbol, a sequence having a length greater than or equal to 2K, formed by complex elements of a Zadoff-Chu sequence of length N, root r and frequency offset equal to the integer value provided by said binary to decimal converter, said Zadoff-Chu sequence generator being configured so that any two K-ary symbols of said plurality are associated with Zadoff-Chu sequences having distinct frequency offsets,
- wherein the distinct frequency offsets for the Zadoff-Chu sequence are assigned distinctively for two communications.
Dependencies are inferred from the claim text.