The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in the present disclosure and are not admitted to be prior art by inclusion in this section.
In some wireless networks such as long term evolution (LTE) networks as defined by various third generation partnership project (3GPP) technical specifications (TSs), a variable guard interval (GI), also known as a variable-length GI, may be used as part of a transmission of an orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) signal (collectively referred to as “OFDM(A) signals” or “OFDM(A) transmit signals”). Specifically, a radio frame in which an OFDM(A) signal is transmitted may include the data payload of the OFDM(A) signal, and the frame may further include a GI between concurrent signals. As used herein, the term “OFDM(A) signal” will be used to refer to the combination of the data payload of the OFDM(A) signal and the GI. In embodiments, the OFDM(A) signal in the frequency domain (FD) may be comprised of a number of OFDM symbols or OFDMA subsymbols (collectively referred to herein as “OFDM(A) symbols”) across a given frequency bandwidth.
In general, the frequency-domain (FD) input signal that may be used to generate the OFDM(A) signal may include data such as a payload data and/or quasi-random reference signals. The FD input signal may occupy a majority of the subcarriers of the radio frame used to transmit the OFDM(A) signal. After an inverse discrete fourier transform is applied to the FD input signal, the resultant time-domain (TD) signal may not include a GI, or may include a GI with a length that is different than the intended length of the GI of the OFDM(A) signal.
USPTO Backgrounds
USPTO Backgrounds