Coarse frequency offset estimation for digital multimedia broadcasting

A method of estimating a coarse frequency offset in Digital Multimedia Broadcasting (DMB) transmission frames, said method comprising:

• receiving said DMB transmission frames comprising a synchronization channel comprising a phase reference symbol;
• circularly shifting said phase reference symbol by applying a circular shift to said phase reference symbol;
• numerically correlating the circularly shifted phase reference symbol with a known correct phase reference symbol to obtain a highest peak and a side peaks of the numeric correlation;
• computing a phase reference symbol angle based on a multiplication of said peak and a carrier spacing of said DMB transmission frames;
• summing said phase reference symbol angle for all of sub carriers within said phase reference symbol;
• computing an average of said highest peak over said DMB transmission frames to reduce effects of said side peaks;
• and
• estimating a coarse frequency offset of said DMB transmission frames based on the computing process.

An apparatus for estimating a coarse frequency offset in Digital Multimedia Broadcasting (DMB) transmission frames, said apparatus comprising:

• a receiver that receives a phase reference symbol;
• a memory unit operatively connected to said receiver and comprising a programmable set of instructions;
• a display unit operatively connected to said memory unit;
• a buffer operatively connected to said memory unit, wherein said buffer comprises data fields for a peak of a correlator output, a frequency offset of said DMB frames, a counter, and a change flag;
• and
• a processor that processes said programmable set of instructions comprising:
• receiving said DMB transmission frames comprising a synchronization channel comprising a phase reference symbol;
• circularly shifting said phase reference symbol by applying a circular shift to said phase reference symbol;
• numerically correlating the circularly shifted phase reference symbol with a known correct phase reference symbol to obtain a highest peak and a side peaks of the numeric correlation;
• computing a phase reference symbol angle based on a multiplication of said peak and a carrier spacing of said DMB transmission frames;
• summing said phase reference symbol angle for all of sub carriers within said phase reference symbol;
• computing an average of said highest peak over said DMB transmission frames to reduce effects of said side peaks if a frequency offset exists in said buffer;
• updating said change flag;
• incrementing said counter;
• and
• determining a buffer entry if said buffer entry with said counter is greater than or equal to a predefined parameter.