Baseband processor and wireless device
A baseband processor includes a modulating unit and a converting unit. The modulating unit generates an orthogonal frequency division multiplexing (OFDM) symbol by modulating a bit stream. The converting unit converts the OFDM symbol from a frequency domain into a time domain, and adjusts a frequency of the OFDM symbol according to a frequency hopping sequence to perform frequency hopping in a digital domain.
1. A baseband processor comprising:
a modulating unit configured to generate an orthogonal frequency division multiplexing (OFDM) symbol by modulating a bit stream; and
a converting unit configured to convert the OFDM symbol from a frequency domain into a time domain, and to adjust a frequency of the OFDM symbol according to a frequency hopping sequence to perform frequency hopping in a digital domain and in the time domain,
wherein the converting unit comprises:
a time-frequency code unit configured to generate a band selection signal based on a time-frequency code corresponding to the frequency hopping sequence;
an IFFT unit configured to convert the OFDM symbol from the frequency domain into the time domain; and
a digital mixer configured to perform the frequency hopping of the converted OFDM symbol in the time domain in response to the band selection signal,
wherein the baseband processor further comprises a digital-to-analog converter configured to convert the OFDM symbol provided from the converting unit from the digital domain into an analog domain, and
wherein the digital-to-analog converter has a sampling rate corresponding to at least two frequency bands.
2. The baseband processor of claim 1 , wherein the digital mixer is further configured to adjust the frequency of the converted OFDM symbol by multiplying the OFDM symbol and a rotation phase corresponding to a frequency band indicated by the band selection signal.
3. The baseband processor of claim 1 , wherein the IFFT unit is a 128-point IFFT unit.
4. The baseband processor of claim 1 , wherein the digital-to-analog converter has the sampling rate of about 1,584 MHz.
5. A baseband processor comprising:
a converting unit configured to receive an orthogonal frequency division multiplexing (OFDM) symbol, to convert the OFDM symbol from a time domain into a frequency domain, and to adjust a frequency of the OFDM symbol according to a frequency hopping sequence to perform frequency de-hopping in a digital domain and in the time domain; and
a demodulating unit configured to generate a bit stream by demodulating the converted OFDM symbol provided from the converting unit,
wherein the converting unit comprises:
a time-frequency code unit configured to generate a band selection signal based on a time-frequency code corresponding to the frequency hopping sequence;
a digital mixer configured to perform the frequency de-hopping in response to the band selection signal to obtain the OFDM symbol in the time domain; and
a fast Fourier transform unit configured to convert the OFDM symbol in the time domain into the OFDM symbol in the frequency domain,
wherein the baseband processor further comprises an analog-to-digital converter configured to provide the OFDM symbol to the converting unit by converting the OFDM symbol from an analog domain into the digital domain, and
wherein the analog-to-digital converter has a sampling rate corresponding to at least two frequency bands.
6. The baseband processor of claim 5 , wherein the digital mixer is further configured to adjust the frequency of the OFDM symbol by multiplying the OFDM symbol and a rotation phase corresponding to a frequency band indicated by the band selection signal.